Filed Pursuant to Rule 424(b)(3)
                                                Registration File No. 333-108273

PROSPECTUS



                                 200,000 SHARES

                           ACACIA RESEARCH CORPORATION

                    ACACIA RESEARCH-COMBIMATRIX COMMON STOCK

                           __________________________

         This prospectus covers the sale of our Acacia Research-CombiMatrix
common stock by the selling security holders identified in this prospectus. We
will not receive any proceeds from the sale of our Acacia Research-CombiMatrix
common stock by the selling security holders.

         Our Acacia Research-CombiMatrix common stock is traded on the Nasdaq
SmallCap Market under the symbol "CBMX."

         On September 9, 2003, the last reported sale price of a share of our
Acacia Research-CombiMatrix common stock on the Nasdaq SmallCap Market was
$3.95.

         INVESTING IN OUR ACACIA RESEARCH-COMBIMATRIX COMMON STOCK INVOLVES
RISKS, SOME OF WHICH ARE DESCRIBED IN THE "RISK FACTORS" SECTION BEGINNING ON
PAGE 4 OF THIS PROSPECTUS.

         NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.







                The date of this prospectus is September 11, 2003



YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS. WE HAVE
NOT AUTHORIZED ANYONE TO PROVIDE YOU WITH INFORMATION DIFFERENT FROM THAT
CONTAINED IN THIS PROSPECTUS. THE SELLING SECURITY HOLDERS ARE OFFERING TO SELL,
AND SEEKING OFFERS TO BUY, SHARES OF ACACIA RESEARCH-COMBIMATRIX COMMON STOCK
ONLY IN JURISDICTIONS WHERE OFFERS AND SALES ARE PERMITTED. THE INFORMATION
CONTAINED IN THIS PROSPECTUS IS ACCURATE ONLY AS OF THE DATE OF THIS PROSPECTUS,
REGARDLESS OF THE TIME OF DELIVERY OF THIS PROSPECTUS OR OF ANY SALE OF THE
SHARES.

                          ____________________________

                                TABLE OF CONTENTS
                                                                            Page
Summary.................................................................     1
Forward Looking Statements..............................................     3
Risk Factors............................................................     4
Use of Proceeds.........................................................     23
Selling Security Holders................................................     23
Plan of Distribution....................................................     24
Experts.................................................................     24
Legal Matters...........................................................     24
Where to Find Additional Information....................................     25
Information Incorporated by Reference...................................     25



                                     SUMMARY

         Acacia Research Corporation develops, acquires and licenses enabling
technologies for the life sciences and media technologies sectors, which
comprise our two business groups.

         Our life sciences business, referred to as the "CombiMatrix group," is
comprised of our wholly-owned subsidiary, CombiMatrix Corporation and
CombiMatrix Corporation's subsidiaries, Advanced Material Sciences, Inc., or
Advanced Material Sciences, and CombiMatrix K.K. Our core technology opportunity
in the life sciences sector has been developed by CombiMatrix Corporation.
CombiMatrix Corporation is a life sciences technology company with a proprietary
system for rapid, cost competitive creation of DNA and other compounds on a
programmable semiconductor chip. This proprietary technology has significant
applications relating to genomic and proteomic research. Advanced Material
Sciences, a development stage company, holds the exclusive license for
CombiMatrix Corporation's biological array processor technology in certain
fields of material sciences. CombiMatrix K.K., an indirect wholly-owned Japanese
corporation located in Tokyo, is exploring opportunities for CombiMatrix
Corporation's active biochip system with academic, pharmaceutical and
biotechnology organizations in the Asian market.

         Our media technologies business, collectively referred to as the
"Acacia Technologies group," owns patented intellectual property in the media
technologies sector. The Acacia Technologies group owns patented digital media
transmission, or DMT, technology enabling the digitization, encryption, storage,
transmission, receipt and playback of digital content. The DMT technology is
protected by five U.S. and seventeen international patents. The DMT technology
is utilized by a variety of companies, including cable companies, hotel in-room
entertainment companies, Internet movie companies, Internet music companies,
on-line adult entertainment companies, on-line learning companies and other
companies that stream audio or audio/video content. The Acacia Technologies
group also owns technology known as the V-chip. The V-chip was adopted by
manufacturers of televisions sold in the U.S. to provide blocking of certain
programming based upon its content rating code, in compliance with the
Telecommunications Act of 1996. The V-chip technology was protected by U.S.
Patent No. 4,554,584, which expired in July 2003.

         Following is a summary of the principal wholly-owned companies that
constitute our two business groups:


      GROUP / COMPANY                       DESCRIPTION OF BUSINESS
      ---------------                       -----------------------

COMBIMATRIX GROUP:

CombiMatrix Corporation             A life sciences technology company with a
                                    proprietary system for rapid, cost
                                    competitive creation of DNA and other
                                    compounds on a programmable semiconductor
                                    chip. This proprietary technology has
                                    significant applications relating to genomic
                                    and proteomic research, biological and
                                    chemical detection and combinatorial
                                    chemistry markets.

                                    Advanced Material Sciences, a development
                                    stage company and majority-owned subsidiary
                                    of CombiMatrix Corporation, holds the
                                    exclusive license for CombiMatrix
                                    Corporation's biological array processor
                                    technology in certain fields of material
                                    sciences.

                                    CombiMatrix K.K., an indirect wholly-owned
                                    Japanese subsidiary of CombiMatrix
                                    Corporation, is exploring opportunities for
                                    CombiMatrix Corporation's active biochip
                                    system with pharmaceutical and biotechnology
                                    companies in the Asian market.

                                       -1-


ACACIA TECHNOLOGIES GROUP:

Acacia Media Technologies           A media technology company that owns
  Corporation                       patented digital media transmission
                                    technology used to digitize, encrypt, store,
                                    transmit, receive and playback digitized
                                    content sent via pathways such as cable,
                                    satellite and the Internet, and covering a
                                    variety of services such as those commonly
                                    known as video-on-demand, audio-on-demand
                                    and streaming media.

Soundview Technologies              A media technology company that owns
  Incorporated                      intellectual property related to the
                                    telecommunications field, including a
                                    television blanking system, also known as
                                    "V-chip," which it licenses to television
                                    manufacturers.

RECAPITALIZATION AND MERGER TRANSACTIONS

         On December 11, 2002, our stockholders voted in favor of a
recapitalization transaction whereby we created two new classes of common stock
called "Acacia Research-CombiMatrix stock," or AR-CombiMatrix stock, and "Acacia
Research-Acacia Technologies stock," or AR-Acacia Technologies stock, and
divided our then-existing Acacia Research common stock into shares of the two
new classes of common stock. AR-CombiMatrix stock is intended to reflect
separately the performance of our CombiMatrix group and to benefit from its
licensing and research and development efforts. AR-Acacia Technologies stock is
intended to reflect separately the performance of our Acacia Technologies group
and to benefit from the licensing of its technologies. In the recapitalization,
which became effective on December 13, 2002, Acacia Research Corporation
stockholders received 0.5582 of a share of AR-CombiMatrix stock, and one share
of AR-Acacia Technologies stock, for each share of Acacia Research common stock
that they owned. Although our AR-CombiMatrix stock and our AR-Acacia
Technologies stock are intended to reflect the performance of our different
business groups, they are both classes of common stock of Acacia Research
Corporation and are not stock issued by the respective groups.

         On December 11, 2002 our stockholders and CombiMatrix Corporation
stockholders also voted in favor of a merger transaction pursuant to which we
acquired the stockholder interests in CombiMatrix Corporation not already owned
by us (52% of the total stockholder interests in CombiMatrix Corporation). The
acquisition was accomplished through a merger, effective December 13, 2002, in
which stockholders of CombiMatrix Corporation other than Acacia Research
Corporation received one share of our new AR-CombiMatrix stock in exchange for
each share of CombiMatrix Corporation common stock that they owned immediately
prior to the merger.

RECENT TRANSACTIONS

         In May 2003, we issued 2,416,502 shares, and warrants to purchase
1,208,252 shares (subject to adjustment under certain circumstances), of our
AR-CombiMatrix stock to certain selling security holders in a private placement.
In July 2003, we issued 295,790 shares of our AR-CombiMatrix stock to certain
selling security holders pursuant to a purchase agreement in which the
consideration for the shares consisted of shares of Advanced Material Sciences,
Inc. common stock. The shares of AR-CombiMatrix stock described above, including
the shares issuable upon the exercise of the warrants described above, are
covered by a registration statement on Form S-3, filed July 7, 2003.

         In July 2003, we issued 200,000 shares of our AR-CombiMatrix stock to
certain selling security holders pursuant to common stock purchase agreements in
which the consideration for the shares consisted of shares of common stock of
CombiMatrix Corporation's CombiMatrix K.K. subsidiary. These shares of
AR-CombiMatrix stock are covered by this prospectus.

         We were incorporated in California in January 1993, and we
reincorporated in Delaware in December 1999. We maintain our executive offices
at 500 Newport Center Drive, 7th Floor, Newport Beach, California 92660, and our
telephone number is (949) 480-8300.

                                       -2-


                           FORWARD-LOOKING STATEMENTS

         This prospectus contains forward-looking statements within the meaning
of the federal securities laws. Forward-looking statements are statements that
predict or describe future events or trends and that do not relate solely to
historical matters. You can generally identify forward-looking statements as
statements containing the words "may," "will," "expect," "believe," "estimate,"
"anticipate," "intend," "continue," and other similar expressions or the
negative of these terms. You should be aware that the matters described in our
forward-looking statements are subject to known and unknown risks, uncertainties
and other unpredictable factors, many of which are beyond our control.
Statements regarding the following subjects are forward-looking by their nature:

         o        our business strategies;

         o        market trends and risks;

         o        assumptions regarding economic conditions;

         o        circumstances affecting anticipated revenues and costs; and

         o        legislative, regulatory and competitive developments.

         These forward-looking statements are subject to various risks and
uncertainties, including those related to:

         o        the recent slowdown affecting technology companies;

         o        our ability to successfully develop products;

         o        rapid technological change in our markets;

         o        anticipated sources of future revenues;

         o        changes in demand for our future products;

         o        our ability to raise capital in the future; and

         o        the adequacy of our capital resources to fund our operations.

         Other risks, uncertainties and factors, including those discussed under
"Risk Factors" in this prospectus or described in reports that we file from time
to time with the Securities and Exchange Commission, such as our Form 10-K and
10-Q, could cause our actual results and those of our industries to differ
materially from those projected in any forward-looking statements we make. We
are not obligated to publicly update or revise any forward-looking statements,
whether as a result of new information, future events or otherwise.

                                      -3-


                                  RISK FACTORS

         AN INVESTMENT IN OUR STOCK INVOLVES A NUMBER OF RISKS. BEFORE MAKING A
DECISION TO PURCHASE OUR STOCK, YOU SHOULD CAREFULLY CONSIDER ALL OF THE RISKS
DESCRIBED IN THIS PROSPECTUS. IF ANY OF THE RISKS DISCUSSED IN THIS PROSPECTUS
ACTUALLY OCCUR, OUR BUSINESS, FINANCIAL CONDITION AND RESULTS OF OPERATIONS
COULD BE MATERIALLY AND ADVERSELY AFFECTED. IF THIS WERE TO OCCUR, THE TRADING
PRICES OF OUR STOCK COULD DECLINE SIGNIFICANTLY AND YOU MAY LOSE ALL OR PART OF
YOUR INVESTMENT.

                                  GENERAL RISKS

THE CONTINUING WORLDWIDE ECONOMIC SLOWDOWN AND RELATED UNCERTAINTIES MAY
CONTINUE TO ADVERSELY IMPACT OUR REVENUES AND OPERATING RESULTS.

         Slower economic activity, concerns about inflation, decreased consumer
confidence, reduced corporate profits and capital spending, adverse business
conditions and liquidity concerns in the technology and biotechnology and
related industries, and recent international conflicts and terrorist and
military activity have resulted in a continuing downturn in worldwide economic
conditions. We cannot predict the timing, strength and duration of any economic
recovery in our industries. In addition, the events of September 11, 2001 and
subsequent international conflicts and terrorist acts can be expected to place
further pressure on economic conditions in the United States and worldwide.
These conditions make it extremely difficult for us to accurately forecast and
plan future business activities. If such conditions continue or worsen, our
business, financial condition and results of operations will likely be
materially and adversely affected.

BECAUSE OUR BUSINESS OPERATIONS ARE SUBJECT TO MANY INHERENT AND UNCONTROLLABLE
RISKS, WE MAY NOT SUCCEED.

         We have significant economic interests in our subsidiary companies. Our
business operations are subject to numerous risks, challenges, expenses and
uncertainties inherent in the establishment of new business enterprises. Many of
these risks and challenges are subject to outside influences over which we have
no control, including:

         o        our subsidiary companies' products and services face uncertain
                  market acceptance;

         o        technological advances may make our subsidiary companies'
                  products and services obsolete or less competitive;

         o        competition is intense in the industries in which our
                  subsidiaries do business;

         o        increases in operating costs, including costs for supplies,
                  personnel and equipment;

         o        the availability and cost of capital;

         o        general economic conditions; and

         o        governmental regulation that excessively restricts our
                  subsidiary companies' businesses.

         We cannot assure you that our subsidiary companies will be able to
market any product or service on a large commercial scale, that our subsidiary
companies will ever achieve or maintain profitable operations or that they, or
we, will be able to remain in business.

WE HAVE A HISTORY OF LOSSES AND EXPECT TO INCUR ADDITIONAL LOSSES IN THE FUTURE.

         We have sustained substantial losses since our inception resulting in
an accumulated deficit, as of June 30, 2003, of $172.4 million (including a
reclassification of accumulated deficit in the amount of $21.7 million to
permanent capital representing the fair value of the ten percent (10%) stock
dividend paid in 2001) on a consolidated basis. We may never become profitable
or if we do, we may never be able to sustain profitability. We expect to incur
significant research and development, marketing, general and administrative
expenses. As a result, we expect to incur significant losses for the foreseeable
future.

                                      -4-


BECAUSE OUR OPERATING RESULTS HAVE FLUCTUATED SIGNIFICANTLY AND MAY CONTINUE TO
DO SO IN THE FUTURE, OUR STOCK PRICES MAY BE VERY VOLATILE.

         Our operating results may vary significantly from quarter to quarter
due to a variety of factors, including:

         o        the operating results of our current and future subsidiary
                  companies;

         o        the nature and timing of our investments in new subsidiary
                  companies;

         o        our decisions to acquire or divest interests in our current
                  and future subsidiaries, which may create changes in losses or
                  income and amortization of goodwill;

         o        changes in our methods of accounting for our current and
                  future subsidiaries, which may cause us to recognize gains or
                  losses under applicable accounting rules;

         o        the timing of the sales of equity interests in our current and
                  future subsidiary companies;

         o        our ability to effectively manage our growth and the growth of
                  our subsidiary companies;

         o        general economic conditions; and

         o        the cost of future acquisitions, which may increase due to
                  intense competition from other potential acquirers of
                  technology-related companies or ideas.

         We have incurred and expect to continue to incur significant expenses
in pursuing and developing new business ventures. To date, we have lacked a
consistent source of recurring revenue. Each of the factors we have described
may cause our stock to be more volatile than the stock of other companies.

BECAUSE CERTAIN OF OUR SUBSIDIARY COMPANIES MAY NOT GENERATE ANY SIGNIFICANT
REVENUES, AND OPERATING RESULTS FROM OUR SUBSIDIARY COMPANIES MAY FLUCTUATE
SIGNIFICANTLY, OUR OWN OPERATING RESULTS MAY BE NEGATIVELY AFFECTED.

         Our operating results may be materially impacted by the operating
results of our subsidiary companies. We cannot assure that these companies will
be able to meet their anticipated working capital needs to develop their
products and services. If they fail to properly develop these products and
services, they will be unable to generate meaningful product sales. We
anticipate that our operating results are likely to vary significantly as a
result of a number of factors, including:

         o        the timing of new product introductions by each subsidiary
                  company;

         o        the stage of development of the business of each subsidiary
                  company;

         o        the technical feasibility of each subsidiary company's
                  technologies and techniques;

         o        the novelty of the technology owned by our subsidiary
                  companies;

         o        the accuracy, effectiveness and reliability of products
                  developed by our subsidiary companies;

         o        the level of product acceptance;

         o        the strength of each subsidiary company's intellectual
                  property rights;

         o        the ability of each subsidiary company to avoid infringing the
                  intellectual property rights of others;

         o        each subsidiary company's ability to exploit and commercialize
                  its technology;

                                      -5-


         o        the volume and timing of orders received and product line
                  maturation;

         o        the impact of price competition; and

         o        each subsidiary company's ability to access distribution
                  channels.

         Many of these factors are beyond our subsidiary companies' control. We
cannot provide any assurance that any subsidiary company will experience growth
in the future or be profitable on an operating basis in any future period.

IF WE, OR OUR SUBSIDIARIES, ENCOUNTER UNFORESEEN DIFFICULTIES AND CANNOT OBTAIN
ADDITIONAL FUNDING ON FAVORABLE TERMS, OUR BUSINESS MAY SUFFER.

         As of June 30, 2003, we had cash and short-term investments of $55.1
million on our consolidated financial statements.

         To date, our subsidiary companies have relied primarily upon selling
equity securities, including sales to and loans from us, to generate the funds
needed to finance implementing their plans of operations. Our subsidiary
companies may be required to obtain additional financing through bank
borrowings, debt or equity financings or otherwise, which would require us to
make additional investments or face a dilution of our equity interests.

         We cannot assure that we will not encounter unforeseen difficulties
that may deplete our capital resources more rapidly than anticipated. Any
efforts to seek additional funds could be made through equity, debt or other
external financings. Nevertheless, we cannot assure that additional funding will
be available on favorable terms, if at all. If we fail to obtain additional
funding when needed for our subsidiary companies and ourselves, we may not be
able to execute our business plans and our business may suffer.

FAILURE TO EFFECTIVELY MANAGE OUR GROWTH COULD PLACE STRAINS ON OUR MANAGERIAL,
OPERATIONAL AND FINANCIAL RESOURCES AND COULD ADVERSELY AFFECT OUR BUSINESS AND
OPERATING RESULTS.

         Our growth has placed, and is expected to continue to place, a
significant strain on our managerial, operational and financial resources.
Further, as our subsidiary companies' businesses grow, we will be required to
manage multiple relationships. Any further growth by us or our subsidiary
companies or an increase in the number of our strategic relationships will
increase this strain on our managerial, operational and financial resources.
This strain may inhibit our ability to achieve the rapid execution necessary to
successfully implement our business plan. In addition, our future success
depends on our ability to expand our organization to match the growth of our
subsidiaries.

OUR FUTURE SUCCESS DEPENDS IN PART ON THE CONTINUED SERVICE OF OUR KEY
EXECUTIVES, AND THE LOSS OF ANY OF THESE KEY EXECUTIVES COULD ADVERSELY AFFECT
OUR BUSINESS AND OPERATING RESULTS.

         Our success depends in part upon the continued service of our executive
officers, particularly Paul R. Ryan, our Chairman and Chief Executive Officer,
Robert L. Harris, II, our President and Dr. Amit Kumar, President and Chief
Executive Officer of CombiMatrix Corporation. Neither Messrs. Ryan or Harris nor
Dr. Kumar has an employment or non-competition agreement with us. The loss of
any of these key individuals would be detrimental to our ongoing operations and
prospects.

OUR FUTURE SUCCESS AND THE SUCCESS OF OUR SUBSIDIARY COMPANIES DEPENDS ON OUR
AND THEIR ABILITIES TO ATTRACT AND RETAIN QUALIFIED TECHNICAL PERSONNEL AND
QUALIFIED MANAGEMENT AND MARKETING TEAMS. FAILURE TO DO SO WOULD HARM OUR
ONGOING OPERATIONS AND BUSINESS PROSPECTS.

         We believe that our success will depend on continued employment by us
and our subsidiary companies of senior management and key technical personnel.
Our subsidiary companies will need to attract, retain and motivate qualified
management personnel to execute their current business plans and to successfully
develop commercially viable products and services. Competition for qualified
personnel is intense and we cannot assure you that we will successfully retain
our existing key employees or attract and retain any additional personnel we may
require.

                                      -6-


         Each of our subsidiary companies has key executives upon whom we
significantly depend, and the success of those subsidiary companies depends on
their ability to retain and motivate those individuals.

BECAUSE WE HAVE A LIMITED OPERATING HISTORY, WE CANNOT ASSURE THAT OUR
OPERATIONS WILL BE PROFITABLE.

         We commenced operations in 1993 and, accordingly, have a limited
operating history. In addition, certain of our subsidiary companies are in the
early stages of development and or operations and have limited operating
histories. You should consider our prospects in light of the risks, expenses and
difficulties frequently encountered by companies with such limited operating
histories. Since we have a limited operating history, we cannot assure you that
our operations will be profitable or that we will generate sufficient revenues
to meet our expenditures and support our activities.

         During the three and six months ended June 30, 2003 and the fiscal year
ended December 31, 2002, we had operating losses of approximately $6.9 million,
$13.8 million and $80.3 million, respectively, and net losses of approximately
$6.8 million $13.4 million and $59.0 million, respectively. If we continue to
incur operating losses, we may not have enough money to expand our business and
our subsidiary companies' businesses in the future.

THE AVAILABILITY OF SHARES FOR SALE IN THE FUTURE COULD REDUCE THE MARKET PRICE
OF OUR COMMON STOCK.

         In the future, we may issue securities to raise cash for acquisitions.
We may also pay for interests in additional subsidiary companies by using a
combination of cash and our common stock or just our common stock. We may also
issue securities convertible into our common stock. Any of these events may
dilute your ownership interest in us and have an adverse impact on the price of
our common stock.

         In addition, sales of a substantial amount of our common stock in the
public market, or the perception that these sales may occur, could reduce the
market price of our common stock. This could also impair our ability to raise
additional capital through the sale of our securities.

DELAWARE LAW AND OUR CHARTER DOCUMENTS CONTAIN PROVISIONS THAT COULD DISCOURAGE
OR PREVENT A POTENTIAL TAKEOVER OF ACACIA RESEARCH CORPORATION THAT MIGHT
OTHERWISE RESULT IN OUR STOCKHOLDERS RECEIVING A PREMIUM OVER THE MARKET PRICE
OF THEIR SHARES.

         Provisions of Delaware law and our certificate of incorporation and
bylaws could make more difficult the acquisition of Acacia Research Corporation
by means of a tender offer, proxy contest or otherwise, and the removal of
incumbent officers and directors. These provisions include:

         o        Section 203 of the Delaware General Corporation Law, which
                  prohibits a merger with a 15%-or-greater stockholder, such as
                  a party that has completed a successful tender offer, until
                  three years after that party became a 15%-or-greater
                  stockholder;

         o        amendment of our bylaws by the stockholders requires a
                  two-thirds approval of the outstanding shares;

         o        the authorization in our certificate of incorporation of
                  undesignated preferred stock, which could be issued without
                  stockholder approval in a manner designed to prevent or
                  discourage a takeover;

         o        provisions in our bylaws eliminating stockholders' rights to
                  call a special meeting of stockholders, which could make it
                  more difficult for stockholders to wage a proxy contest for
                  control of our board of directors or to vote to repeal any of
                  the anti-takeover provisions contained in our certificate of
                  incorporation and bylaws; and

         o        the division of our board of directors into three classes with
                  staggered terms for each class, which could make it more
                  difficult for an outsider to gain control of our board of
                  directors.

         Such potential obstacles to a takeover could adversely affect the
ability of our stockholders to receive a premium price for their stock in the
event another company wants to acquire us.

                                      -7-


                   RISKS RELATING TO A CAPITAL STRUCTURE WITH
                      TWO SEPARATE CLASSES OF COMMON STOCK

HOLDERS OF BOTH CLASSES OF OUR STOCK ARE STOCKHOLDERS OF ONE COMPANY, AND THE
FINANCIAL PERFORMANCE OF ONE GROUP COULD AFFECT THE OTHER, THUS EXPOSING THE
HOLDERS OF EACH GROUP'S STOCK TO THE RISKS OF AN INVESTMENT IN THE ENTIRE
COMPANY.

         Holders of AR-CombiMatrix stock and AR-Acacia Technologies stock are
stockholders of a single company. The CombiMatrix group and the Acacia
Technologies group are not separate legal entities. As a result, stockholders
will continue to be subject to all of the risks of an investment in Acacia
Research Corporation and all of our businesses, assets and liabilities. The
issuance of our AR-CombiMatrix stock and our AR-Acacia Technologies stock and
the allocation of assets and liabilities and stockholders' equity between the
CombiMatrix group and the Acacia Technologies group did not result in a
distribution or spin-off to stockholders of any of our assets or liabilities and
did not affect ownership of our assets or responsibility for our liabilities or
those of our subsidiaries. The assets we attribute to one group could be subject
to the liabilities of the other group, whether such liabilities arise from
lawsuits, contracts or indebtedness that we attribute to the other group. If we
are unable to satisfy one group's liabilities out of the assets we attribute to
it, we may be required to satisfy those liabilities with assets we have
attributed to the other group.

         Financial effects from one group that affect our consolidated results
of operations or financial condition could, if significant, affect the results
of operations or financial condition of the other group and the market price of
the common stock relating to the other group. In addition, net losses of either
group and dividends or distributions on, or repurchases of, either class of
common stock will reduce the funds we can pay as dividends on each class of
common stock under Delaware law. For these reasons, you should read our
consolidated financial information with the financial information we provide for
each group.

THE HOLDERS OF AR-COMBIMATRIX STOCK AND THE HOLDERS OF AR-ACACIA TECHNOLOGIES
STOCK HAVE ONLY LIMITED SEPARATE STOCKHOLDER RIGHTS.

         Holders of AR-CombiMatrix stock and AR-Acacia Technologies stock have
the rights customarily held by common stockholders. They also have these
specific rights related to their corresponding group:

         o        certain rights with regard to dividends and liquidation;

         o        requirements for a mandatory dividend, redemption or
                  conversion upon the disposition of all or substantially all of
                  the assets of their corresponding group; and

         o        a right to vote on matters as a separate voting class in the
                  limited circumstances provided under Delaware law, by stock
                  exchange rules or as determined by our board of directors
                  (such as an amendment of our certificate of incorporation that
                  changes the rights, privileges or preferences of the class of
                  stock held by such stockholders).

         We will not hold separate stockholder meetings for holders of
AR-CombiMatrix stock and AR-Acacia Technologies stock.

THE HOLDERS OF AR-COMBIMATRIX STOCK AND THE HOLDERS OF AR-ACACIA TECHNOLOGIES
STOCK WILL HAVE CERTAIN LIMITS ON THEIR RESPECTIVE VOTING POWERS.

         GROUP COMMON STOCK WITH A MAJORITY OF VOTING POWER CAN CONTROL VOTING
         OUTCOMES.

         The holders of AR-CombiMatrix stock and AR-Acacia Technologies stock
will vote together as a single class, except in limited circumstances. If a
separate vote on a matter by the holders of either our AR-CombiMatrix stock or
our AR-Acacia Technologies stock is not required under Delaware law or by stock
exchange rules, and if our board of directors does not require a separate vote,
either class of common stock that is entitled to more than the number of votes
required to approve such matter could control the outcome of such vote - even if
the matter involves a divergence or conflict of the interests between the
holders of our AR-CombiMatrix stock and our AR-Acacia Technologies stock. In
addition, if the holders of common stock having a majority of the voting power
of all shares of common stock outstanding approve a merger, the terms of which
did not require separate class voting under stock exchange rules, then the

                                      -8-


merger could be consummated - even if the holders of a majority of either class
of common stock were to vote against the merger.

         GROUP COMMON STOCK WITH LESS THAN MAJORITY VOTING POWER CAN BLOCK
         ACTION IF A CLASS VOTE IS REQUIRED.

         If Delaware law, stock exchange rules or our board of directors
requires a separate vote on a matter by the holders of either our AR-CombiMatrix
stock or our AR-Acacia Technologies stock, such as a proposal to amend the terms
of one class of stock, those holders could prevent approval of the matter, even
if the holders of a majority of the total number of votes cast or entitled to be
cast, voting together as a class, were to vote in favor of it.

         HOLDERS OF ONLY ONE CLASS OF COMMON STOCK CANNOT ENSURE THAT THEIR
         VOTING POWER WILL BE SUFFICIENT TO PROTECT THEIR INTERESTS.

         Since the relative voting power per share of AR-CombiMatrix stock and
AR-Acacia Technologies stock will fluctuate based on the market values of the
two classes of common stock, the relative voting power of a class of common
stock could decrease. As a result, holders of shares of only one of the two
classes of common stock cannot ensure that their voting power will be sufficient
to protect their interests.

OUR RESTATED CERTIFICATE OF INCORPORATION MAY BE AMENDED TO INCREASE OR DECREASE
THE AUTHORIZED SHARES OF EITHER CLASS OF COMMON STOCK WITHOUT THE APPROVAL OF
EACH CLASS VOTING SEPARATELY.

         Our restated certificate of incorporation provides that an amendment to
our restated certificate to increase or decrease the number of authorized shares
of either class of common stock will require the approval of the holders of a
majority of the voting power of all shares of common stock, voting together as a
single class, and will not require the approval of each class of stock voting as
a separate class. Accordingly, if the holders of one class of common stock hold
a majority of the voting power of all shares of common stock, then that majority
could approve an amendment to our restated certificate to increase or decrease
the authorized shares of stock of either class without the approval of the
holders of the minority class of stock.

STOCKHOLDERS MAY NOT HAVE ANY REMEDIES FOR BREACH OF FIDUCIARY DUTIES IF ANY
ACTION BY OUR DIRECTORS OR OFFICERS HAS A DISADVANTAGEOUS EFFECT ON EITHER CLASS
OF COMMON STOCK.

         Stockholders may not have any remedies if any action or decision of our
directors and officers has a disadvantageous effect on either class of common
stock compared to the other class of common stock. We are not aware of any legal
precedent under Delaware law involving the fiduciary duties of directors and
officers of corporations having two classes of common stock, or separate classes
or series of capital stock, the rights of which, like our AR-CombiMatrix stock
and AR-Acacia Technologies stock, are defined by reference to separate
businesses of the corporation.

         Principles of Delaware law established in cases involving differing
treatment of two classes of capital stock or two groups of holders of the same
class of capital stock provide that a board of directors owes an equal duty to
all stockholders regardless of class or series. Under these principles of
Delaware law and the related principle known as the "business judgment rule,"
absent abuse of discretion, a good faith business decision made by a
disinterested and adequately informed board of directors, board of directors'
committee or officer with respect to any matter having different effects on
holders of AR-CombiMatrix stock and holders of AR-Acacia Technologies stock
would be a defense to any challenge to such determination made by or on behalf
of the holders of either class of common stock.

         As of June 30, 2003, our executive officers, directors and their
affiliates beneficially owned approximately 11% of the outstanding
AR-CombiMatrix stock and 20% of the outstanding AR-Acacia Technologies stock.

                                      -9-


NUMEROUS POTENTIAL CONFLICTS OF INTERESTS EXIST BETWEEN OUR AR-COMBIMATRIX STOCK
AND OUR AR-ACACIA TECHNOLOGIES STOCK WHICH MAY BE DIFFICULT TO RESOLVE BY OUR
BOARD OR WHICH MAY BE RESOLVED ADVERSELY TO ONE OF THE CLASSES.

         The existence of separate classes of common stock could give rise to
occasions when the interests of the holders of AR-CombiMatrix stock and
AR-Acacia Technologies stock diverge or conflict. Examples include
determinations by our directors or officers to:

         o        pay or omit the payment of dividends on AR-CombiMatrix stock
                  or AR-Acacia Technologies stock;

         o        allocate consideration to be received by holders of each of
                  the classes of common stock in connection with a merger or
                  consolidation involving Acacia Research Corporation;

         o        convert one class of common stock into shares of the other;

         o        approve certain dispositions of the assets of either group;

         o        allocate the proceeds of future issuances of our stock either
                  to the Acacia Technologies group or the CombiMatrix group;

         o        allocate corporate opportunities between the groups; and

         o        make other operational and financial decisions with respect to
                  one group that could be considered detrimental to the other
                  group.

         When making decisions with regard to matters that create potential
diverging or conflicting interests, our directors and officers will act in
accordance with their fiduciary duties, the terms of our restated certificate of
incorporation, and, to the extent applicable, our management and allocation
policies.

         THE PERFORMANCE OF ONE GROUP OR THE DIVIDENDS PAID TO ONE GROUP MAY
         ADVERSELY AFFECT THE DIVIDENDS AVAILABLE FOR THE OTHER GROUP.

         Our board of directors currently has no intention to pay dividends on
our AR-CombiMatrix stock or our AR-Acacia Technologies stock. Determinations as
to future dividends on our AR-CombiMatrix stock and our AR-Acacia Technologies
stock will be based primarily on the financial condition, results of operations
and business requirements of the relevant group and Acacia Research Corporation
as a whole. Subject to the limitations referred to below, our board of directors
has the authority to declare and pay dividends on our AR-CombiMatrix stock and
our AR-Acacia Technologies stock in any amount and could, in its sole
discretion, declare and pay dividends exclusively on our AR-CombiMatrix stock,
exclusively on our AR-Acacia Technologies stock, or on both, in equal or unequal
amounts. Our board of directors will not be required to consider the amount of
dividends previously declared on each class, the respective voting or
liquidation rights of each class or any other factor.

         The performance of one group may cause our board of directors to pay
more or less dividends on the common stock relating to the other group than if
that other group was a stand-alone company. In addition, Delaware law and our
restated certificate of incorporation impose limitations on the amount of
dividends which may be paid on each class of common stock.

         PROCEEDS OF MERGERS OR CONSOLIDATIONS MAY BE ALLOCATED UNFAVORABLY.

         Our restated certificate of incorporation does not contain any
provisions governing how consideration to be received by holders of common stock
in connection with a merger or consolidation involving Acacia Research
Corporation is to be allocated among holders of each class of common stock. Our
board of directors will determine the percentage of the consideration to be
allocated to holders of each class of common stock in any such transaction. Such
percentage may be materially more or less than that which might have been
allocated to such holders had our board of directors chosen a different method
of allocation.

                                      -10-


         HOLDERS OF EITHER CLASS OF COMMON STOCK MAY BE ADVERSELY AFFECTED BY A
         CONVERSION OF GROUP COMMON STOCK.

         Our board of directors could, in its sole discretion and without
stockholder approval, determine to convert shares of AR-Acacia Technologies
stock into shares of AR-CombiMatrix stock, or vice versa, at a time when either
or both classes of common stock may be considered to be overvalued or
undervalued. Any such conversion would dilute the interests in Acacia Research
Corporation of the holders of the class of common stock being issued in the
conversion. It could also give holders of shares of the class of common stock
converted a greater or lesser premium than any premium that might be paid by a
third-party buyer of all or substantially all of the assets of the group whose
stock is converted.

         HOLDERS OF EITHER CLASS OF COMMON STOCK COULD BE ADVERSELY AFFECTED BY
         A DISPOSITION OF THE ASSETS ATTRIBUTED TO THEIR RESPECTIVE GROUPS.

         Our board of directors could, in its sole discretion and without
stockholder approval, determine to dispose of all or substantially all the
assets of a group. If a disposition of group assets occurs at a time when those
assets are considered undervalued, then holders of that group's stock would
receive less consideration than they could have received had the assets been
disposed of at a time when they had a higher value.

         PROCEEDS OF FUTURE ISSUANCES OF OUR STOCK COULD BE ALLOCATED
         UNFAVORABLY.

         We may in the future issue a new class of stock, such as a class of
preferred stock, or additional shares of AR-CombiMatrix stock or AR-Acacia
Technologies stock. Proceeds from any future issuance of any class of stock
would be attributed among the CombiMatrix group or the Acacia Technologies group
as determined by our board of directors. There is no requirement that the
proceeds from an issuance of AR-CombiMatrix stock or AR-Acacia Technologies
stock be attributed to the corresponding group. Such allocations might be
materially more or less for the respective groups than what might have been
attributed had our board of directors chosen a different allocation method.
Also, any designated preferred class may be designed to reflect the performance
of Acacia Research Corporation as a whole, rather than the performance of the
CombiMatrix group or the Acacia Technologies group.

         ALLOCATION OF CORPORATE OPPORTUNITIES COULD FAVOR ONE GROUP OVER
         ANOTHER.

         Our board of directors may be required to allocate corporate
opportunities between the groups. In some cases, our directors could determine
that a corporate opportunity, such as a business that we are acquiring, should
be shared by the groups. Any such decisions could favor one group at the expense
of the other.

         OTHER OPERATIONAL AND FINANCIAL DECISIONS WHICH MAY FAVOR ONE GROUP
         OVER THE OTHER.

         Our board of directors or our senior officers will review other
operational and financial matters affecting the CombiMatrix group and the Acacia
Technologies group, including the allocation of financing resources and capital,
technology and know-how and corporate overhead, taxes, debt, interest and other
matters. Any decision of our board of directors or our senior officers in these
matters could favor one group at the expense of the other.

OUR BOARD OF DIRECTORS MAY CHANGE OUR MANAGEMENT AND ALLOCATION POLICIES WITHOUT
STOCKHOLDER APPROVAL TO THE DETRIMENT OF EITHER GROUP.

         Our board of directors may modify or rescind our policies with respect
to the allocation of corporate overhead, taxes, debt, interest and other
matters, or may adopt additional policies, in its sole discretion without
stockholder approval. A decision to modify or rescind these policies, or adopt
additional policies could have different effects on holders of either class of
common stock or could result in a benefit or detriment to one class of
stockholders compared to the other class. Our board of directors will make any
such decision in accordance with its good faith business judgment that the
decision is in the best interests of Acacia Research Corporation and all of our
stockholders as a whole.

EITHER GROUP MAY FINANCE THE OTHER GROUP ON TERMS UNFAVORABLE TO ONE OF THE
GROUPS.

         We may transfer cash and other property between groups to finance their
business activities. The group providing the financing will be subject to the
risks relating to the group receiving the financing. We will account for those

                                      -11-


transfers generally as a short-term or long-term loan between groups or as a
repayment of a previous borrowing.

THERE ARE LIMITS ON THE CONSIDERATION WHICH MAY BE RECEIVED BY THE STOCKHOLDERS
IN THE EVENT OF THE DISPOSITION OF ASSETS OF A GROUP.

         Our restated certificate of incorporation provides that if a
disposition of all or substantially all of the properties and assets of either
group occurs, we must, subject to certain exceptions:

         o        distribute through a dividend or redemption to holders of the
                  class of common stock relating to such group an amount equal
                  to the net proceeds of such disposition; or

         o        convert at a 10% premium such common stock into shares of the
                  class of common stock relating to the other group.

         If the group subject to the disposition were a separate, independent
company and its shares were acquired by another person, certain costs of that
disposition, including corporate level taxes, might not be payable in connection
with that acquisition. As a result, stockholders of the separate, independent
company might receive a greater amount than the net proceeds that would be
received by holders of the class of common stock relating to that group if the
assets of such group were sold. In addition, we cannot assure you that the net
proceeds per share of the common stock relating to that group will be equal to
or more than the market value per share of such common stock prior to or after
announcement of a disposition.

         The term "substantially all of the properties and assets" of a group is
subject to potentially conflicting interpretations. Resolution of such a dispute
could adversely impact the holders of either the class of common stock related
to the assets being disposed or the holders of the other class because the
consideration, if any, to be received by the holders of the class related to the
disposed assets may depend on whether the disposition involved "substantially
all" of the properties and assets of that class.

HOLDERS OF EITHER CLASS OF COMMON STOCK MAY BE ADVERSELY AFFECTED BY A
REDEMPTION OF THEIR COMMON STOCK.

         We are entitled to redeem the outstanding common stock relating to a
group when all or substantially all of that group's assets are sold. We can
redeem the assets for cash, securities, a combination of cash and securities or
other property at fair value. A disposition-related redemption could occur when
the assets being disposed of are considered undervalued. If that were the case,
the holders of our common stock related to that group would receive less
consideration for their shares than they may deem reasonable.

         We can also redeem on a pro rata basis all of the outstanding shares of
a group's common stock for shares of the common stock of one or more of our
wholly owned subsidiaries. If this were to occur, the holders of the redeemed
class of common stock would no longer have stockholder voting rights in Acacia
Research Corporation or any other benefits to be derived from holding a class of
stock in Acacia Research Corporation. In addition, if the outstanding shares of
a class of our common stock are redeemed for shares that are not publicly
traded, the holders of such redeemed stock will no longer be able to publicly
trade their shares and accordingly their investment will be substantially less
liquid.

OUR CAPITAL STRUCTURE AND THE VARIABLE VOTE PER SHARE COULD ENABLE A POTENTIAL
ACQUIRER TO TAKE CONTROL OF OUR COMPANY THROUGH THE ACQUISITION OF ONLY ONE OF
THE CLASSES OF OUR COMMON STOCK.

         A potential acquirer could acquire control of Acacia Research
Corporation by acquiring shares of common stock having a majority of the voting
power of all shares of common stock outstanding. Such a majority could be
obtained by acquiring a sufficient number of shares of both classes of common
stock or, if one class of common stock has a majority of such voting power, only
shares of that class. Currently, our AR-CombiMatrix stock has a majority of the
voting power. As a result, currently, it might be possible for an acquiror to
obtain control of Acacia Research Corporation by purchasing only shares of
AR-CombiMatrix stock.

                                      -12-


DECISIONS BY DIRECTORS AND OFFICERS THAT AFFECT DIFFERENTLY ONE CLASS OF OUR
COMMON STOCK COMPARED TO THE OTHER COULD ADVERSELY AFFECT THE MARKET VALUE OF
EITHER OR BOTH OF THE CLASSES OF OUR COMMON STOCK.

         The relative voting power per share of our AR-CombiMatrix stock and our
AR-Acacia Technologies stock and the number of shares of one class of common
stock issuable upon the conversion of the other class of common stock will vary
depending upon the relative market values of our AR-CombiMatrix stock and our
AR-Acacia Technologies stock. The market value of either or both classes of
common stock could be affected by market reaction to decisions by our board of
directors or our management that investors perceive to affect differently one
class of common stock compared to the other. These decisions could involve
changes to our management and allocation policies, allocations of corporate
opportunities and financing resources between groups, and changes in dividend
policies.

INVESTORS MAY NOT VALUE OUR AR-COMBIMATRIX STOCK AND OUR AR-ACACIA TECHNOLOGIES
STOCK BASED ON GROUP FINANCIAL INFORMATION AND POLICIES.

         We cannot assure you that investors will value our AR-CombiMatrix stock
and our AR-Acacia Technologies stock based on the reported financial results and
prospects of the separate groups or the dividend policies established by our
board of directors with respect to those groups. Holders of AR-CombiMatrix stock
and AR-Acacia Technologies stock will continue to be common stockholders of
Acacia Research Corporation subject to all the risks associated with an
investment in Acacia Research Corporation as a whole. Additionally, the separate
stockholder rights related to each group are limited and relate to events that
may never occur, such as dividend and liquidation rights and the disposition of
all or substantially all of the assets of a group. Accordingly, investors may
discount the value of AR-CombiMatrix stock and AR-Acacia Technologies stock
because both groups are part of a common enterprise rather than a stand-alone
entity and each class of stock has limited separate stockholder rights.

HOLDERS OF AR-COMBIMATRIX STOCK AND AR-ACACIA TECHNOLOGIES STOCK MAY NOT RECEIVE
A PREMIUM FROM AN INVESTOR ACQUIRING CONTROL OF THEIR RESPECTIVE CLASSES OF
STOCK.

         Control of AR-CombiMatrix stock or AR-Acacia Technologies stock may not
provide control of Acacia Research Corporation as a whole. Accordingly, unlike
many acquisition transactions, holders of AR-CombiMatrix stock and
AR-Technologies stock may not receive a controlling interest premium from an
investor acquiring control of their respective classes of stock.

THERE ARE CERTAIN PROVISIONS IN OUR TWO-CLASS CAPITAL STRUCTURE THAT COULD HAVE
ANTITAKEOVER EFFECTS.

         The existence of the two classes of common stock could, under certain
circumstances, prevent stockholders from profiting from an increase in the
market value of their shares as a result of a change in control of Acacia
Research Corporation by delaying or preventing such change in control. The
existence of two classes of common stock could present complexities and could,
in certain circumstances, pose obstacles, financial and otherwise, to an
acquiring person. We could, in the sole discretion of our board of directors and
without stockholder approval, exercise the right to convert the shares of one
class of common stock into shares of the other at a 10% premium over their
respective average market values. This conversion could result in additional
dilution to persons seeking control of Acacia Research Corporation.

         Our board of directors could issue shares of preferred stock or common
stock that could be used to create voting or other impediments to discourage
persons seeking to gain control of Acacia Research Corporation, and preferred
stock could also be privately placed with purchasers favorable to our board of
directors in opposing such action.

                                      -13-


                     RISKS RELATING TO THE COMBIMATRIX GROUP

         The risk factors beginning on this page discuss risks relating to the
CombiMatrix group. Because each holder of AR-CombiMatrix stock is a holder of
the common stock of one company, Acacia Research Corporation, the risks
associated with the Acacia Technologies group could affect our AR-CombiMatrix
stock. As such, we also urge you to read carefully the section "Risks Relating
to the Acacia Technologies Group" below.

THE COMBIMATRIX GROUP HAS A HISTORY OF LOSSES AND EXPECTS TO INCUR ADDITIONAL
LOSSES IN THE FUTURE.

         The CombiMatrix group has sustained substantial losses since its
inception. The CombiMatrix group may never become profitable or if it does, it
may never be able to sustain profitability. We expect the CombiMatrix group to
incur significant research and development, marketing, general and
administrative expenses. As a result, we expect the CombiMatrix group to incur
significant losses for the foreseeable future.

THE COMBIMATRIX GROUP MAY FAIL TO MEET MARKET EXPECTATIONS BECAUSE OF
FLUCTUATIONS IN ITS QUARTERLY OPERATING RESULTS, WHICH COULD CAUSE ITS STOCK
PRICE TO DECLINE.

         The CombiMatrix group's revenues and operating results have fluctuated
in the past and may continue to fluctuate significantly from quarter to quarter
in the future. It is possible that in future periods the CombiMatrix group's
revenues could fall below the expectations of securities analysts or investors,
which could cause the market price of our AR-CombiMatrix stock to decline. The
following are among the factors that could cause the CombiMatrix group's
operating results to fluctuate significantly from period to period:

         o        its unpredictable revenue sources, as described below;

         o        the nature, pricing and timing of the CombiMatrix group's and
                  its competitors' products;

         o        changes in the CombiMatrix group's and its competitors'
                  research and development budgets;

         o        expenses related to, and the CombiMatrix group's ability to
                  comply with, governmental regulations of its products and
                  processes; and

         o        expenses related to, and the results of, patent filings and
                  other proceedings relating to intellectual property rights.

         The CombiMatrix group anticipates significant fixed expenses due in
part to its need to continue to invest in product development. It may be unable
to adjust its expenditures if revenues in a particular period fail to meet its
expectations, which would harm its operating results for that period. As a
result of these fluctuations, the CombiMatrix group believes that
period-to-period comparisons of the CombiMatrix group's financial results will
not necessarily be meaningful, and you should not rely on these comparisons as
an indication of its future performance.

THE COMBIMATRIX GROUP'S REVENUES WILL BE UNPREDICTABLE, AND THIS MAY HARM ITS
FINANCIAL CONDITION.

         The amount and timing of revenues that the CombiMatrix group may
realize from its business will be unpredictable because:

         o        whether products are commercialized and generate revenues
                  depends, in part, on the efforts and timing of its potential
                  customers;

         o        its sales cycles may be lengthy; and

         o        it cannot be sure as to the timing of receipt of payment for
                  its products.

         As a result, the CombiMatrix group's revenues may vary significantly
from quarter to quarter, which could make its business difficult to manage and
cause its quarterly results to be below market expectations. If this happens,
the price of the CombiMatrix group's common stock may decline significantly.

                                      -14-


TECHNOLOGY COMPANY STOCK PRICES ARE ESPECIALLY VOLATILE, AND THIS VOLATILITY MAY
DEPRESS THE PRICE OF OUR AR-COMBIMATRIX STOCK.

         The stock market has experienced significant price and volume
fluctuations, and the market prices of technology companies, particularly
biotechnology companies, has been highly volatile. We believe that various
factors may cause the market price of our AR-CombiMatrix stock to fluctuate,
perhaps substantially, including, among others, announcements of:

         o        its or its competitors' technological innovations;

         o        developments or disputes concerning patents or proprietary
                  rights;

         o        supply, manufacturing or distribution disruptions or other
                  similar problems;

         o        proposed laws regulating participants in the biotechnology
                  industry;

         o        developments in relationships with collaborative partners or
                  customers;

         o        its failure to meet or exceed securities analysts'
                  expectations of its financial results; or

         o        a change in financial estimates or securities analysts'
                  recommendations.

         In the past, companies that have experienced volatility in the market
price of their stock have been the objects of securities class action
litigation. If our AR-CombiMatrix stock was the object of securities class
action litigation, it could result in substantial costs and a diversion of
management's attention and resources, which could materially harm the business
and financial results of the CombiMatrix group.

THE COMBIMATRIX GROUP IS DEPLOYING NEW AND UNPROVEN TECHNOLOGIES WHICH MAKES
EVALUATION OF ITS BUSINESS AND PROSPECTS DIFFICULT AND IT MAY BE FORCED TO CEASE
OPERATIONS IF IT DOES NOT DEVELOP COMMERCIALLY SUCCESSFUL PRODUCTS.

         The CombiMatrix group has not proven its ability to commercialize
products on a large scale. In order to successfully commercialize products on a
large scale, it will have to make significant investments, including investments
in research and development and testing, to demonstrate their technical benefits
and cost-effectiveness. Problems frequently encountered in connection with the
commercialization of products using new and unproven technologies might limit
its ability to develop and commercialize its products. For example, the
CombiMatrix group's products may be found to be ineffective, unreliable or
otherwise unsatisfactory to potential customers. The CombiMatrix group may
experience unforeseen technical complications in the processes it uses to
develop, manufacture, customize or receive orders for its products. These
complications could materially delay or limit the use of products the
CombiMatrix group attempts to commercialize, substantially increase the
anticipated cost of its products or prevent it from implementing its processes
at appropriate quality and scale levels, thereby causing its business to suffer.

THE COMBIMATRIX GROUP MAY NEED TO RAISE ADDITIONAL CAPITAL IN THE FUTURE, AND IF
ADDITIONAL CAPITAL IS NOT AVAILABLE ON ACCEPTABLE TERMS, THE COMBIMATRIX GROUP
MAY HAVE TO CURTAIL OR CEASE OPERATIONS.

         The CombiMatrix group's future capital requirements will be substantial
and will depend on many factors including how quickly it commercializes its
products, the progress and scope of its collaborative and independent research
and development projects, the filing, prosecution, enforcement and defense of
patent claims and the need to obtain regulatory approval for certain products in
the United States or elsewhere. Changes may occur that would cause the
CombiMatrix group's available capital resources to be consumed significantly
sooner than it expects.

         The CombiMatrix group may be unable to raise sufficient additional
capital on favorable terms or at all. If it fails to do so, it may have to
curtail or cease operations or enter into agreements requiring it to relinquish
rights to certain technologies, products or markets because it will not have the
capital necessary to exploit them.

                                      -15-


IF THE COMBIMATRIX GROUP DOES NOT ENTER INTO SUCCESSFUL PARTNERSHIPS AND
COLLABORATIONS WITH OTHER COMPANIES, IT MAY NOT BE ABLE TO FULLY DEVELOP ITS
TECHNOLOGIES OR PRODUCTS, AND ITS BUSINESS WOULD BE HARMED.

         Since the CombiMatrix group does not possess all of the resources
necessary to develop and commercialize products that may result from its
technologies on a mass scale, it will need either to grow its sales, marketing
and support group or make appropriate arrangements with strategic partners to
market, sell and support its products. The CombiMatrix group believes that it
will have to enter into additional strategic partnerships to develop and
commercialize future products. If it does not enter into adequate agreements, or
if its existing arrangements or future agreements are not successful, its
ability to develop and commercialize products will be impacted negatively, and
its revenues will be adversely affected.

         The current business of the CombiMatrix group is substantially
dependent on its existing arrangement with Roche. The CombiMatrix group
currently relies upon payments by Roche for a majority of its future revenues
and expends a majority of its resources toward fulfilling its contractual
obligations to Roche. Roche's primary service to the CombiMatrix group is to
distribute and proliferate its technology platform. If the CombiMatrix group
were to lose its relationship with Roche, the CombiMatrix group would be
required to establish a distribution agreement with another partner or
distribute its technology platform itself. This could prove difficult,
time-consuming and expensive, and the CombiMatrix group may not be successful in
achieving this objective.

THE COMBIMATRIX GROUP HAS LIMITED EXPERIENCE COMMERCIALLY MANUFACTURING,
MARKETING OR SELLING ANY OF ITS POTENTIAL PRODUCTS, AND UNLESS IT DEVELOPS THESE
CAPABILITIES, IT MAY NOT BE SUCCESSFUL.

         Even if the CombiMatrix group is able to develop its products for
commercial release on a large-scale, it has limited experience in manufacturing
its products in the volumes that will be necessary for it to achieve commercial
sales and in marketing or selling its products to potential customers. We cannot
assure you that the CombiMatrix group will be able to commercially produce its
products on a timely basis, in sufficient quantities or on commercially
reasonable terms.

THE COMBIMATRIX GROUP FACES INTENSE COMPETITION AND WE CANNOT ASSURE YOU THAT IT
WILL BE SUCCESSFUL.

         The CombiMatrix group expects to compete with companies that design,
manufacture and market instruments for analysis of genetic variation and
function and other applications using established sequential and parallel
testing technologies. The CombiMatrix group is also aware of other biotechnology
companies that have or are developing testing technologies for the SNP
genotyping, gene expression profiling and proteomic markets. The CombiMatrix
group anticipates that it will face increased competition in the future as new
companies enter the market with new technologies and its competitors improve
their current products.

         The markets for the CombiMatrix group's products are characterized by
rapidly changing technology, evolving industry standards, changes in customer
needs, emerging competition and new product introductions. One or more of the
CombiMatrix group's competitors may offer technology superior to those of the
CombiMatrix group and render its technology obsolete or uneconomical. Many of
its competitors have greater financial and personnel resources and more
experience in marketing, sales and research and development than it has. Some of
its competitors currently offer arrays with greater density than it does and
have rights to intellectual property, such as genomic information or proprietary
technology, which provides them with a competitive advantage. If the CombiMatrix
group were not able to compete successfully, its business and financial
condition would be materially harmed.

                                      -16-


IF THE COMBIMATRIX GROUP'S NEW AND UNPROVEN TECHNOLOGY IS NOT USED BY
RESEARCHERS IN THE PHARMACEUTICAL, BIOTECHNOLOGY AND ACADEMIC COMMUNITIES, ITS
BUSINESS WILL SUFFER.

         The CombiMatrix group's products may not gain market acceptance. In
that event, it is unlikely that its business will succeed. Biotechnology and
pharmaceutical companies and academic research centers have historically
analyzed genetic variation and function using a variety of technologies, and
many of them have made significant capital investments in existing technologies.
Compared to existing technologies, the CombiMatrix group's technologies are new
and unproven. In order to be successful, its products must meet the commercial
requirements of the biotechnology, pharmaceutical and academic communities as
tools for the large-scale analysis of genetic variation and function. Market
acceptance will depend on many factors, including:

         o        the development of a market for its tools for the analysis of
                  genetic variation and function, the study of proteins and
                  other purposes;

         o        the benefits and cost-effectiveness of its products relative
                  to others available in the market;

         o        its ability to manufacture products in sufficient quantities
                  with acceptable quality and reliability and at an acceptable
                  cost;

         o        its ability to develop and market additional products and
                  enhancements to existing products that are responsive to the
                  changing needs of its customers;

         o        the willingness and ability of customers to adopt new
                  technologies requiring capital investments or the reluctance
                  of customers to change technologies in which they have made a
                  significant investment; and

         o        the willingness of customers to transmit test data and permit
                  the CombiMatrix group to transmit test results over the
                  Internet, which will be a necessary component of its product
                  and services packages unless customers purchase or license its
                  equipment for use in their own facilities.

IF THE MARKET FOR ANALYSIS OF GENOMIC INFORMATION DOES NOT DEVELOP OR IF GENOMIC
INFORMATION IS NOT AVAILABLE TO THE COMBIMATRIX GROUP'S POTENTIAL CUSTOMERS, ITS
BUSINESS WILL NOT SUCCEED.

         The CombiMatrix group is designing its technology primarily for
applications in the biotechnology, pharmaceutical and academic communities. The
usefulness of the CombiMatrix group's technology depends in part upon the
availability of genomic data. The CombiMatrix group is initially focusing on
markets for analysis of genetic variation and function, namely SNP genotyping
and gene expression profiling. These markets are new and emerging, and they may
not develop as the CombiMatrix group anticipates, or at all. Also, researchers
may not seek or be able to convert raw genomic data into medically valuable
information through the analysis of genetic variation and function. If genomic
data is not available for use by the CombiMatrix group's customers or if its
target markets do not emerge in a timely manner, or at all, demand for its
products will not develop as it expects, and it may never become profitable.

THE COMBIMATRIX GROUP'S FUTURE SUCCESS DEPENDS ON THE CONTINUED SERVICE OF ITS
ENGINEERING, TECHNICAL AND KEY MANAGEMENT PERSONNEL AND ITS ABILITY TO IDENTIFY,
HIRE AND RETAIN ADDITIONAL ENGINEERING, TECHNICAL AND KEY MANAGEMENT PERSONNEL.

         There is intense competition for qualified personnel in the CombiMatrix
group's industry, particularly for engineers and senior level management. Loss
of the services of, or failure to recruit, engineers or other technical and key
management personnel could be significantly detrimental to the group and could
adversely affect its business and operating results. The CombiMatrix group may
not be able to continue to attract and retain engineers or other qualified
personnel necessary for the development of its products and business or to
replace engineers or other qualified personnel who may leave the group in the
future. The CombiMatrix group's anticipated growth is expected to place
increased demands on its resources and likely will require the addition of new
management personnel.

                                      -17-


THE EXPANSION OF THE COMBIMATRIX GROUP'S PRODUCT LINES MAY SUBJECT IT TO
REGULATION BY THE UNITED STATES FOOD AND DRUG ADMINISTRATION AND FOREIGN
REGULATORY AUTHORITIES, WHICH COULD PREVENT OR DELAY ITS INTRODUCTION OF NEW
PRODUCTS.

         If the CombiMatrix group manufactures, markets or sells any products
for any regulated clinical or diagnostic applications, those products will be
subject to extensive governmental regulation as medical devices in the United
States by the FDA and in other countries by corresponding foreign regulatory
authorities. The process of obtaining and maintaining required regulatory
clearances and approvals is lengthy, expensive and uncertain. Products that
CombiMatrix Corporation manufactures, markets or sells for research purposes
only are not subject to governmental regulations as medical devices or as
analyte specific reagents to aid in disease diagnosis. We believe that the
CombiMatrix group's success will depend upon commercial sales of improved
versions of products, certain of which cannot be marketed in the United States
and other regulated markets unless and until the CombiMatrix group obtains
clearance or approval from the FDA and its foreign counterparts, as the case may
be. Delays or failures in receiving these approvals may limit our ability to
benefit from new CombiMatrix group products.

AS THE COMBIMATRIX GROUP'S OPERATIONS EXPAND, ITS COSTS TO COMPLY WITH
ENVIRONMENTAL LAWS AND REGULATIONS WILL INCREASE, AND FAILURE TO COMPLY WITH
THESE LAWS AND REGULATIONS COULD HARM ITS FINANCIAL RESULTS.

         The CombiMatrix group's operations involve the use, transportation,
storage and disposal of hazardous substances, and as a result it is subject to
environmental and health and safety laws and regulations. As the CombiMatrix
group expands its operations, its use of hazardous substances will increase and
lead to additional and more stringent requirements. The cost to comply with
these and any future environmental and health and safety regulations could be
substantial. In addition, the CombiMatrix group's failure to comply with laws
and regulations, and any releases of hazardous substances into the environment
or at its disposal sites, could expose the CombiMatrix group to substantial
liability in the form of fines, penalties, remediation costs and other damages,
or could lead to a curtailment or shut down of its operations. These types of
events, if they occur, would adversely impact the group's financial results.

THE COMBIMATRIX GROUP'S BUSINESS DEPENDS ON ISSUED AND PENDING PATENTS, AND THE
LOSS OF ANY PATENTS OR THE GROUP'S FAILURE TO SECURE THE ISSUANCE OF PATENTS
COVERING ELEMENTS OF ITS BUSINESS PROCESSES WOULD MATERIALLY HARM ITS BUSINESS
AND FINANCIAL CONDITION.

         The CombiMatrix group's success depends on its ability to protect and
exploit its intellectual property. The CombiMatrix group currently has two
patents issued in the United States, one patent issued in Europe and more than
44 patent applications pending in the United States, Europe and elsewhere. The
patent application process before the Unites States Patent and Trademark Office
and other similar agencies in other countries is initially confidential in
nature. Patents that are filed outside the United States, however, are published
approximately eighteen months after filing. The CombiMatrix group cannot
determine in a timely manner whether patent applications covering technology
that competes with its technology have been filed in the United States or other
foreign countries or which, if any, will ultimately issue or be granted as
enforceable patents. Some of the CombiMatrix group's patent applications may
claim compositions, methods or uses that may also be claimed in patent
applications filed by others. In some or all of these applications, a
determination of priority of inventorship may need to be decided in a proceeding
before the United States Patent and Trademark Office or a foreign regulatory
body or a court. If the CombiMatrix group is unsuccessful in these proceedings,
it could be blocked from further developing, commercializing or selling
products. Regardless of the ultimate outcome, this process is time-consuming and
expensive.

ANY INABILITY TO ADEQUATELY PROTECT THE COMBIMATRIX GROUP'S PROPRIETARY
TECHNOLOGIES COULD MATERIALLY HARM THE COMBIMATRIX GROUP'S COMPETITIVE POSITION
AND FINANCIAL RESULTS.

         If the CombiMatrix group does not protect its intellectual property
adequately, competitors may be able to use its technologies and erode any
competitive advantage that it may have. The laws of some foreign countries do
not protect proprietary rights to the same extent as the laws of the United
States, and many companies have encountered significant problems in protecting
their proprietary rights abroad. These problems can be caused by the absence of
rules and methods for defending intellectual property rights.

         The patent positions of companies developing tools for the
biotechnology, pharmaceutical and academic communities, including the
CombiMatrix group's patent position, generally are uncertain and involve complex

                                      -18-


legal and factual questions. The CombiMatrix group will be able to protect its
proprietary rights from unauthorized use by third parties only to the extent
that its proprietary technologies are covered by valid and enforceable patents
or are effectively maintained as trade secrets. The CombiMatrix group's existing
patents and any future issued or granted patents it obtains may not be
sufficiently broad in scope to prevent others from practicing its technologies
or from developing competing products. There also is a risk that others may
independently develop similar or alternative technologies or designs around the
CombiMatrix group's patented technologies. In addition, others may oppose or
invalidate its patents, or its patents may fail to provide it with any
competitive advantage. Enforcing the CombiMatrix group's intellectual property
rights may be difficult, costly and time-consuming and ultimately may not be
successful.

         The CombiMatrix group also relies upon trade secret protection for its
confidential and proprietary information. While it has taken security measures
to protect its proprietary information, these measures may not provide adequate
protection for its trade secrets or other proprietary information. The
CombiMatrix group seeks to protect its proprietary information by entering into
confidentiality and invention disclosure and transfer agreements with employees,
collaborators and consultants. Nevertheless, employees, collaborators or
consultants may still disclose its proprietary information, and the CombiMatrix
group may not be able to meaningfully protect its trade secrets. In addition,
others may independently develop substantially equivalent proprietary
information or techniques or otherwise gain access to its trade secrets.

ANY LITIGATION TO PROTECT THE COMBIMATRIX GROUP'S INTELLECTUAL PROPERTY OR ANY
THIRD-PARTY CLAIMS OF INFRINGEMENT, COULD DIVERT SUBSTANTIAL TIME AND MONEY FROM
THE COMBIMATRIX GROUP'S BUSINESS AND COULD SHUT DOWN SOME OF ITS OPERATIONS.

         The CombiMatrix group's commercial success depends in part on its
non-infringement of the patents or proprietary rights of third parties. Many
companies developing tools for the biotechnology and pharmaceutical industries
use litigation aggressively as a strategy to protect and expand the scope of
their intellectual property rights. Accordingly, third parties may assert that
the CombiMatrix group is employing their proprietary technology without
authorization. In addition, third parties may claim that use of the CombiMatrix
group's technologies infringes their current or future patents. The CombiMatrix
group could incur substantial costs and the attention of its management and
technical personnel could be diverted while defending ourselves against any of
these claims. The CombiMatrix group may incur the same liabilities in enforcing
its patents against others. The CombiMatrix group has not made any provision in
its financial plans for potential intellectual property related litigation, and
it may not be able to pursue litigation as aggressively as competitors with
substantially greater financial resources.

         If parties making infringement claims against the CombiMatrix group are
successful, they may be able to obtain injunctive or other equitable relief,
which effectively could block the CombiMatrix group's ability to further
develop, commercialize and sell products, and could result in the award of
substantial damages against it. If the CombiMatrix group is unsuccessful in
protecting and expanding the scope of its intellectual property rights, its
competitors may be able to develop, commercialize and sell products that compete
with it using similar technologies or obtain patents that could effectively
block its ability to further develop, commercialize and sell its products. In
the event of a successful claim of infringement against the CombiMatrix group,
we may be required to pay substantial damages and either discontinue those
aspects of its business involving the technology upon which it infringed or
obtain one or more licenses from third parties. While the CombiMatrix group may
license additional technology in the future, it may not be able to obtain these
licenses at a reasonable cost, or at all. In that event, it could encounter
delays in product introductions while it attempts to develop alternative methods
or products, which may not be successful. Defense of any lawsuit or failure to
obtain any of these licenses could prevent it from commercializing available
products.

                                      -19-


                 RISKS RELATING TO THE ACACIA TECHNOLOGIES GROUP

         The risk factors beginning on this page discuss risks relating to the
Acacia Technologies group. Because each holder of AR-Acacia Technologies stock
is a holder of the common stock of one company, Acacia Research Corporation, and
the risks associated with the CombiMatrix group could affect the AR-Acacia
Technologies stock. As such, we also urge you to read carefully the section
"Risks Relating to the CombiMatrix Group" above.

THE ACACIA TECHNOLOGIES GROUP HAS INCURRED LOSSES IN THE PAST AND EXPECTS TO
INCUR ADDITIONAL LOSSES IN THE FUTURE.

         The Acacia Technologies group has sustained substantial losses in the
past. We expect the Acacia Technologies group to incur significant research and
development, marketing, general and administrative expenses. As a result, we
expect the Acacia Technologies group to incur significant losses for the
foreseeable future.

THE V-CHIP TECHNOLOGY PATENT HELD BY THE ACACIA TECHNOLOGIES GROUP EXPIRED IN
JULY 2003, AND IF THE GROUP DOES NOT DEVELOP OTHER RECURRING SOURCES OF REVENUE,
ITS FINANCIAL CONDITION WILL BE ADVERSELY IMPACTED.

         The Acacia Technologies group, and Acacia Research Corporation as a
whole, has generated substantially all of its revenues from licensing the V-chip
technology to television manufacturers. The Acacia Technologies group's patent
on the V-chip technology expired in July 2003. The Acacia Technologies group
will not be able to collect royalties for televisions containing V-chip
technology sold after the expiration of that patent, but it may still collect
revenues from the sale of such televisions in the U.S. before that date. The
Acacia Technologies group is beginning to market its digital media transmission
technology and is developing other technologies and products. The eventual
licensing and sale of these technologies is intended to replace the revenue
currently being generated by licensing its V-chip technology. If the Acacia
Technologies group does not succeed in developing such technologies or is unable
to commercially license its existing and future technologies, its financial
condition will be adversely impacted.

THE ACACIA TECHNOLOGIES GROUP MAY FAIL TO MEET MARKET EXPECTATIONS BECAUSE OF
FLUCTUATIONS IN ITS QUARTERLY OPERATING RESULTS, WHICH COULD CAUSE THE PRICE OF
AR-ACACIA TECHNOLOGIES STOCK TO DECLINE.

         The Acacia Technologies group revenues and operating results have
fluctuated in the past and may continue to fluctuate significantly from quarter
to quarter in the future. It is possible that in future periods the Acacia
Technologies group's revenues could fall below the expectations of securities
analysts or investors, which could cause the market price of our AR-Acacia
Technologies stock to decline. The following are among the factors that could
cause the Acacia Technologies group's operating results to fluctuate
significantly from period to period:

         o        its unpredictable revenue sources, as described below;

         o        costs related to acquisitions, alliances, licenses and other
                  efforts to expand its operations;

         o        the timing of payments under the terms of any customer or
                  license agreements into which the Acacia Technologies group
                  may enter; and

         o        expenses related to, and the results of, patent filings and
                  other proceedings relating to intellectual property rights.

THE ACACIA TECHNOLOGIES GROUP'S REVENUES WILL BE UNPREDICTABLE, AND THIS MAY
HARM ITS FINANCIAL CONDITION.

         The amount and timing of revenues that the Acacia Technologies group
may realize from its business will be unpredictable because:

         o        whether the Acacia Technologies group generates revenues
                  depends, in part, on the success of its licensing efforts;

         o        its cycle of obtaining licensees may be lengthy; and

                                      -20-


         o        it cannot be sure as to the timing of receipt of payment.

         As a result, the Acacia Technologies group's revenues may vary
significantly from quarter to quarter, which could make its business difficult
to manage and cause its quarterly results to be below market expectations. If
this happens, the price of our AR-Acacia Technologies stock may decline
significantly.

TECHNOLOGY COMPANY STOCK PRICES ARE ESPECIALLY VOLATILE, AND THIS VOLATILITY MAY
DEPRESS THE PRICE OF OUR AR-ACACIA TECHNOLOGIES STOCK.

         The stock market has experienced significant price and volume
fluctuations, and the market prices of technology companies have been highly
volatile. We believe that various factors may cause the market price of our
AR-Acacia Technologies stock to fluctuate, perhaps substantially, including,
among others, announcements of:

         o        its or its competitors' technological innovations;

         o        developments or disputes concerning patents or proprietary
                  rights;

         o        developments in relationships with licensees;

         o        its failure to meet or exceed securities analysts'
                  expectations of its financial results; or

         o        a change in financial estimates or securities analysts'
                  recommendations.

         In the past, companies that have experienced volatility in the market
price of their stock have been the objects of securities class action
litigation. If our AR-Acacia Technologies stock was the object of securities
class action litigation, it could result in substantial costs and a diversion of
management's attention and resources, which could materially harm the business
and financial results of the Acacia Technologies group.

THE ACACIA TECHNOLOGIES GROUP FACES INTENSE COMPETITION, AND WE CANNOT ASSURE
YOU THAT IT WILL BE SUCCESSFUL.

         Although the Acacia Technologies group believes that Acacia Media
Technologies has marketing and licensing rights to enforceable patents and other
intellectual property relating to video and audio on demand, the Acacia
Technologies group cannot assure you that other companies will not develop
competing technologies that offer better or less expensive alternatives to those
offered by Acacia Media Technologies. In the event a competing technology
emerges, Acacia Media Technologies would expect substantial additional
competition.

THE MARKETS SERVED BY THE ACACIA TECHNOLOGIES GROUP ARE SUBJECT TO RAPID
TECHNOLOGICAL CHANGE, AND IF THE ACACIA TECHNOLOGIES GROUP IS UNABLE TO DEVELOP
AND INTRODUCE NEW PRODUCTS, ITS REVENUES COULD STOP GROWING OR COULD DECLINE.

         The markets served by the Acacia Technologies group frequently undergo
transitions in which products rapidly incorporate new features and performance
standards on an industry-wide basis. Products for communications applications,
as well as for high-speed computing applications, are based on continually
evolving industry standards. A significant portion of the Acacia Technologies
group's revenues in recent periods has been, and is expected to continue to be,
derived from licensing of technologies based on existing transmission standards.
The Acacia Technologies group's ability to compete in the future will, however,
depend on its ability to identify and ensure compliance with evolving industry
standards.

THE ACACIA TECHNOLOGIES GROUP'S SUCCESS IS BASED ON ITS ABILITY TO PROTECT ITS
PROPRIETARY TECHNOLOGY AND ITS ABILITY TO DEFEND ITSELF AGAINST INFRINGEMENT
CLAIMS.

         The success of the Acacia Technologies group relies, to varying
degrees, on its proprietary rights and their protection or exclusivity. Although
reasonable efforts will be taken to protect the Acacia Technologies group's
proprietary rights, the complexity of international trade secret, copyright,
trademark and patent law, and common law, coupled with limited resources and the
demands of quick delivery of products and services to market, create risk that
these efforts will prove inadequate. For example, in our pending litigation
against certain television manufacturers alleging their infringement of
Soundview Technologies' V-chip patent, a motion for summary judgment filed by

                                      -21-


the defendants was granted in September 2002. The court ruled that the
defendants did not infringe on Soundview Technologies' patent. If we are
unsuccessful in our intended appeal of this ruling, legal principles will
preclude us from claiming infringement of our patents by other parties.
Accordingly, if we are unsuccessful in this or other litigation to protect our
intellectual property rights, the future revenues of the Acacia Technologies
group could be adversely affected.

         From time to time, the Acacia Technologies group may be subject to
third-party claims in the ordinary course of business, including claims of
alleged infringement of proprietary rights. Any such claims may harm the Acacia
Technologies group by subjecting it to significant liability for damage and
invalidating its proprietary rights. These types of claims, with or without
merit, could subject the Acacia Technologies group to costly litigation and
diversion of its technical and management personnel. The Acacia Technologies
group depends largely on the protection of enforceable patent rights. The Acacia
Technologies group has applications on file with the U.S. Patent and Trademark
Office seeking patents on its core technologies and has patents or rights to
patents that have been issued. We cannot assure you that the pending patent
applications of the Acacia Technologies group will be issued, that third parties
will not violate, or attempt to invalidate these intellectual property rights,
or that certain aspects of those intellectual property will not be
reverse-engineered by third parties without violating the patent rights of the
Acacia Technologies group.

         For Acacia Media Technologies and Soundview Technologies, proprietary
rights constitute their only significant assets. The Acacia Technologies group
also owns licenses from third parties and it is possible that it could become
subject to infringement actions based upon such licenses. The Acacia
Technologies group generally obtains representations as to the origin and
ownership of such licensed content. However, this may not adequately protect the
Acacia Technologies group. The Acacia Technologies group enters into
confidentiality agreements with third parties and generally limits access to
information relating to its proprietary rights. Despite these precautions, third
parties may be able to gain access to and use the Acacia Technologies group's
proprietary rights to develop competing technologies and products with similar
or better features and prices. Any substantial unauthorized use of the Acacia
Technologies group's proprietary rights could materially and adversely affect
its business and operational results.

                                      -22-


                                 USE OF PROCEEDS

         We will not receive any proceeds from the sale of the shares by the
selling security holders. All proceeds from the sale of the shares will go to
the selling security holder who offers and sells the shares.

                            SELLING SECURITY HOLDERS

         The shares of AR-CombiMatrix stock offered by this prospectus have been
or will be issued to the selling security holders (or their assignees) directly
by us. The 200,000 shares of AR-CombiMatrix stock covered by this prospectus
were issued to certain selling security holders pursuant to common stock
purchase agreements in which the consideration for the shares consisted of
shares of common stock of CombiMatrix Corporation's CombiMatrix K.K. subsidiary.

         The following table sets forth (i) the names of the selling security
holders; (ii) the number of outstanding shares of AR-CombiMatrix stock
beneficially owned and the percentage ownership of the selling security holders
prior to the offering, (iii) the aggregate number of shares of AR-CombiMatrix
stock offered by the selling security holders pursuant to this prospectus, and
(iv) the number of shares of AR-CombiMatrix stock beneficially owned by the
selling security holders and the percentage ownership assuming the sale of all
of the shares offered by the selling security holders pursuant to this
prospectus. The information in the table below is current as of the date of this
prospectus. The shares are being registered to permit public secondary trading
of the shares, and the selling security holders may offer the shares for resale
from time to time.



                                                                                 NUMBER
                                                                                 OF
                                                      AR-COMBIMATRIX SHARES      SHARES         AR-COMBIMATRIX SHARES
                                                     BENEFICIALLY OWNED PRIOR    BEING        BENEFICIALLY OWNED AFTER
                          NAME                             TO OFFERING           OFFERED            OFFERING(1)
      ---------------------------------------------- -------------------------  ---------     --------------------------
                                                       NUMBER    PERCENTAGE(2)                 NUMBER      PERCENTAGE(2)
                                                       ------    -------------                 ------      -------------
                                                                                                
      Marubeni Corporation                             140,000         *         140,000           0           0.0%
      Marubeni America Corporation                      60,000         *          60,000           0           0.0%
                                                      ---------     -----       ---------      ------        -------
      TOTAL.........................................   200,000         *%        200,000           0           0.0%


*         Less than 1%.
(1)       The information provided in the table with respect to a selling
          security holder has been obtained from that selling security holder.
          Because the selling security holders may sell all or some portion of
          the shares of our AR-CombiMatrix stock beneficially owned by them and
          because we cannot estimate the number of shares of our AR-CombiMatrix
          stock that will be beneficially owned by the selling security holders
          after this offering, we have assumed for purposes of this table that
          all of the shares offered by the selling security holders have been
          sold pursuant to this prospectus.
(2)       Percentages are based upon the assumption that upon the completion of
          this offering the selling security holders have sold the shares of our
          AR-CombiMatrix stock listed as "Number of Shares Being Offered" and
          are computed on the basis of 25,931,402 shares of AR-CombiMatrix stock
          outstanding as of August 26, 2003.

                                      -23-


                              PLAN OF DISTRIBUTION

         The shares of AR-CombiMatrix stock offered by this prospectus may be
sold by the selling security holders or by their respective pledgees, donees,
transferees or other successors in interest. Such sales may be made at fixed
prices that may be changed, at market prices prevailing at the time of sale, at
prices related to such prevailing market prices, or at negotiated prices, and
may be made on the Nasdaq SmallCap Market, or any exchange on which our
AR-CombiMatrix stock may then be listed. The shares may be sold by one or more
of the following:

         o        one or more block trades in which a broker or dealer so
                  engaged will attempt to sell all or a portion of the shares
                  held by the selling security holders as agent but may position
                  and resell a portion of the block as principal to facilitate
                  the transaction;

         o        purchase by a broker or dealer as principal and resale by such
                  broker or dealer as principal and resale by such broker or
                  dealer for its account under this prospectus;

         o        ordinary brokerage transactions and transactions in which the
                  broker solicits purchasers; and

         o        privately negotiated transactions between the selling security
                  holders and purchasers without a broker-dealer.

         The selling security holders may effect such transactions by selling
shares to or through broker dealers, and such broker-dealers will receive
compensation in negotiated amounts in the form of discounts, concessions,
commissions or fees from the selling security holders and/or the purchasers of
the shares for whom such broker-dealers may act as agent or to whom they sell as
principal, or both (which compensation to a particular broker-dealer might be in
excess of customary commissions). Such brokers or dealers or other participating
brokers or dealers and the selling security holders may be deemed to be
"underwriters" within the meaning of the Securities Act, in connection with such
sales. Except for customary selling commissions in ordinary brokerage
transactions, any such underwriter or agent will be identified, and any
compensation paid to such persons will be described, in a prospectus supplement.
In addition, any securities covered by this prospectus that qualify for sale
under Rule 144 might be sold under Rule 144 rather than under this prospectus.

                                     EXPERTS

         The financial statements of Acacia Research Corporation incorporated in
this prospectus by reference to the Annual Report on Form 10-K of Acacia
Research Corporation, for the year ended December 31, 2002 have been so
incorporated in reliance on the report of PricewaterhouseCoopers LLP,
independent accountants, given on the authority of said firm as experts in
auditing and accounting.

         The financial statements of Acacia Technologies Group (a division of
Acacia Research Corporation) incorporated in this Prospectus by reference to the
Annual Report on Form 10-K of Acacia Research Corporation for the year ended
December 31, 2002 have been so incorporated in reliance on the report of
PricewaterhouseCoopers LLP, independent accountants, given on the authority of
said firm as experts in auditing and accounting.

         The financial statements of CombiMatrix Group (a division of Acacia
Research Corporation) incorporated in this Prospectus by reference to the Annual
Report on Form 10-K of Acacia Research Corporation for the year ended December
31, 2002 have been so incorporated in reliance on the report of
PricewaterhouseCoopers LLP, independent accountants, given on the authority of
said firm as experts in auditing and accounting.


                                  LEGAL MATTERS

         The validity of the shares of our AR-CombiMatrix stock offered hereby
has been passed upon for us by Allen Matkins Leck Gamble & Mallory LLP, Century
City, California.

                                      -24-


                      WHERE TO FIND ADDITIONAL INFORMATION

         We file annual, quarterly and special reports, proxy statements and
other information with the Securities and Exchange Commission, referred to as
the SEC. You may read and copy any document we file at the SEC's Public
Reference Room 1034, 450 Fifth Street, N.W., Washington, D.C. 20549. Please call
the SEC at 1-800-SEC-0330 for further information on the public reference room.
Our SEC filings are also available to the public at the SEC's web site at
HTTP://WWW.SEC.GOV. You may also read and copy this information at the National
Association of Securities Dealers, Inc., 1735 K Street, N.W., Washington, D.C.
20006.

         We maintain a site on the Internet at HTTP://WWW.ACACIARESEARCH.COM.
The information contained in our website is not part of this prospectus and you
should not rely on it in deciding whether or not to purchase our securities.

         We have filed a registration statement, of which this prospectus is a
part, covering the offered securities. As allowed by SEC rules, this prospectus
does not include all of the information contained in the registration statement
and the included exhibits, financial statements and schedules. We refer you to
the registration statement, the included exhibits, financial statements and
schedules for further information. This prospectus is qualified in its entirety
by such other information

                      INFORMATION INCORPORATED BY REFERENCE

         The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be a part of this prospectus, and later information that we file
with the SEC will automatically update and supersede this information. This
prospectus incorporates by reference the documents listed below, and any future
filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the
Securities Exchange Act of 1934, as amended, (the "Exchange Act") until the
selling security holders sell all of the shares offered herein. This prospectus
is part of a registration statement we filed with the SEC. The documents we
incorporate by reference are:

         1.    Our Annual Report on Form 10-K for the fiscal year ended December
               31, 2002, filed March 27, 2003;

         2.    Our Quarterly Report on Form 10-Q for the fiscal quarter ended
               March 31, 2003, filed on May 9, 2003;

         3.    Our Quarterly Report on Form 10-Q for the fiscal quarter ended
               June 30, 2003, filed on August 12, 2003;

         4.    The description of our AR-CombiMatrix stock contained in our
               Registration Statement on Form 8-A, filed December 19, 2002; and

         5.    All documents filed by us pursuant to Sections 13(a), 13(c), 14
               and 15(d) of the Exchange Act, after the date of this
               Registration Statement and prior to the filing of a
               post-effective amendment to this Registration Statement which
               indicates that all securities offered hereunder have been sold,
               or which deregisters all securities then remaining unsold under
               this Registration Statement, shall be deemed to be incorporated
               by reference in this Registration Statement and to be a part
               hereof from the date of filing of such documents.

         We will provide without charge a copy of these filings or, to each
person, including any beneficial owner, to whom a copy of this prospectus is
delivered, upon such person's written or oral request, a copy of any and all of
the information incorporated by reference in this prospectus, other than
exhibits to such documents, unless such exhibits are specifically incorporated
by reference into the information that this prospectus incorporates. Requests
should be directed to the Secretary at Acacia Research Corporation, 500 Newport
Center Drive, 7th Floor, Newport Beach, California 92660, telephone: (949)
480-8300.

                                      -25-


                                 200,000 SHARES



                           ACACIA RESEARCH CORPORATION



                    ACACIA RESEARCH-COMBIMATRIX COMMON STOCK





                          _____________________________

                                   PROSPECTUS
                         ______________________________











                               SEPTEMBER 11, 2003