<Page>

                                SUPPLY AGREEMENT

                             Eos Biotechnology, Inc.

                                Affymetrix, Inc.


CONFIDENTIAL

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<Table>
<Caption>
                                    CONTENTS

<S>    <C>                                                                                 <C>
1.     INTRODUCTION.........................................................................1
2.     DEFINITIONS..........................................................................1
3.     PROBE ARRAY SUPPLY...................................................................5
4.     AFFYMETRIX PROPRIETARY RIGHTS........................................................8
5.     COMPENSATION.........................................................................8
6.     INTELLECTUAL PROPERTY...............................................................13
7.     CONFIDENTIALITY.....................................................................14
8.     WARRANTY............................................................................14
9.     INDEMNITY...........................................................................15
10.    TERM,  TERMINATION AND EFFECT OF TERMINATION........................................16
11.    MISCELLANEOUS.......................................................................17
EXHIBIT A: INITIAL FORECAST................................................................21
EXHIBIT B: CURRENT CUSTOM PROBE ARRAY PRICING..............................................22
EXHIBIT C: EXPRESSION PROBE ARRAY USE RIGHTS FOR SERVICE AND DATABASE RECIPIENTS...........23
EXHIBIT D: LETTER FROM DAVID W. MARTIN, JR., M.D., TO SUSAN E. SIEGEL, DATED 06/23/00......24
EXHIBIT E: EXPRESSION ARRAY RIGHTS FOR NOT-FOR-PROFIT SAMPLE PROVIDERS.....................25
EXHIBIT F: REQUEST FOR CREDIT FORM FOR PROBE ARRAYS AND CUSTOM PROBE ARRAYS................26
</Table>

CONFIDENTIAL

<Page>

                                    AGREEMENT
This agreement ("Agreement") is effective as of March 30, 2001 ("Effective
Date") between Affymetrix, Inc. ("Affymetrix") a Delaware corporation having its
principal place of business at 3380 Central Expressway, Santa Clara, California
95051, and Eos Biotechnology, Inc. ("Eos") a Delaware corporation having its
principal place of business at 225A Gateway Boulevard, South San Francisco, CA
94080 and supercedes the Chip Supply Agreement between the parties effective May
1, 1998.

1        INTRODUCTION

1.1      Affymetrix has research, development, and manufacturing capabilities
         and facilities, and has developed certain rights relevant to DNA probe
         array based technology.
1.2      Eos has research and development capabilities, and facilities to
         conduct research and development activities for the generation of
         databases useful in life sciences research and has developed certain
         rights relative to such databases and probe array based technology.
1.3      Affymetrix and Eos desire to enter into an agreement whereby Affymetrix
         will provide certain licenses to Eos and supply Eos with DNA probe
         arrays for use in Expression Research, development of Database products
         and Services.
1.4      In consideration of the mutual covenants and promises contained in this
         Agreement, Affymetrix and Eos agree as follows:

2        DEFINITIONS

2.1      "Affiliate" shall mean any corporation, company, partnership, joint
         venture, firm or other business entity that is controlled by or
         controls a Party or is under common control with a Party, but only for
         so long as such Affiliate remains an Affiliate of a Party. and only if
         such Affiliate is bound by the terms of this Agreement. For purposes of
         this Section, "control" shall mean, in the case of corporations (or
         equivalents of corporations), direct or indirect ownership or control
         of at least 80% of the voting stock or other ownership interest of such
         entity or, in the case of partnerships, at least 80% of the ownership
         interest in such partnership. Each Party shall be liable to the other
         Party for breach of this Agreement by any of such Party's Affiliates,
         and any such breach shall be deemed a breach by such party.
2.2      "Bona Fide Collaboration(s)" shall mean a scientific collaboration
         between Eos or any of its Affiliates and a third party under a written
         contract and research plan in a specified area, in which a) such third
         party receives the biological materials and/or proprietary information
         of Eos and/or its Affiliates, or in which Eos and/or its Affiliates
         obtains the biological materials and/or proprietary information of the
         third party, and b) Eos or the third party obtains or Eos and the third
         party share between them co-exclusive therapeutic and diagnostic
         proprietary rights and marketing rights to products resulting from the
         collaboration ("For-Profit Collaborators"); provided, however, if the
         Collaborator is a non-commercial, academic entity, then Eos shall
         obtain no less than [***] exclusive license.

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         (under commercial reasonable terms) under all right, title and interest
         in products and proprietary rights resulting from the collaboration,
         and c) the collaboration is within Eos' normal (as of the Effective
         Date) business model (for purposes of this Agreement, "Eos' normal
         business model" shall include, for example, pharmaceutical research and
         development); and d) in which Eos and its Collaborator provide
         significant scientific input to the collaboration in addition to data
         obtained from the Probe Arrays where "significant scientific input"
         includes, for example, material input to [***], material contributions
         to [***], material contribution of [***] and/or material [***], and e)
         in which, at the time the gene expression information is generated,
         such gene expression information is generated primarily for use by Eos
         for the purpose of researching, developing and/or [***]. By way of
         example, Bona Fide Collaborations shall not include business
         relationships based, in significant part, on a contract in which Eos
         provides contract services for a third party involving use of the Probe
         Arrays on a fee-for-service or similar basis. Bona Fide Collaborations
         shall not provide for the access of the Probe Arrays to a company that
         engages in a bona fide business in the sale of probe array based assays
         or services.
2.3      "Chip Improvement Inventions" shall mean all inventions that are
         conceived or first reduced to practice by an employee or contractor of
         a Party or its Affiliates resulting from use of Probe Arrays supplied
         hereunder, and specifically those relating to probe array manufacturing
         techniques, probe array layouts, probe array packaging techniques,
         probe array assay techniques (but only insofar as such assay techniques
         relate to processes after nucleic acid extraction and are directly
         related to arrays of nucleic acid probes), and probe array software
         analysis techniques relating to the extraction of data from probe
         arrays and storing such data in a computer file, but not including
         software analysis techniques for later processing of such data. Chip
         Improvement Inventions shall not include any other inventions that are
         conceived of or reduced to practice by an employee or contractor of a
         Party or its Affiliates including, for example, expression data or
         discoveries resulting therefrom (except for the specific inventions
         described herein above), targets identified through the use of the
         Probe Arrays, or correlations between genetic sequences and function.
2.4      "Confidential Information" shall mean all information and materials,
         patentable or otherwise, of a Party disclosed by or on behalf of such
         Party to the other Party and which derive value to a Party from not
         being generally known, including, but not limited to DNA sequences,
         vectors, cells, substances, formulations, techniques, methodology,
         equipment, data, reports, know-how, trade secrets, preclinical and
         clinical trials and the results thereof, sources of supply, patent
         positioning, and business plans, including any negative developments.
         Without limiting the foregoing, Eos acknowledges and agrees that Chip
         Improvement Inventions are the Confidential Information of Affymetrix.
2.5      "Database" shall mean a collection of Datapoints directly derived from
         a Probe Array and made available for license broadly in whole or in
         part for use to derive additional information. If Eos utilizes a larger
         database to create directly a more limited database for license to a
         third party, it is understood that the Datapoints made available to the
         third party

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         are from the original, larger Database unless the smaller Database is
         made broadly available to other third parties. In the event that data
         are provided on a service basis and later released for commercial
         distribution as a database, such collection of data shall be considered
         a "Service" at the time delivered to a single customer and a "Database"
         when later distributed more broadly.
2.6      "Datapoint" shall mean array data up to and including the expression
         levels of a Gene represented on a Probe Array and comprises all probe
         pairs on the array that represent the Gene.
2.7      "Demonstration Database" shall refer to a database of gene expression
         data that contains no more than [***] Datapoints and is used for
         promotional or marketing purposes without charge.
2.8      "Eos" Area Of Interest" shall mean the use of Probe Arrays as a
         research tool to generate gene expression data for Expression Research,
         generating Databases for external license and/or providing fee-based
         Services to third parties.
2.9      "Expression Research" shall mean Eos' internal research, Eos' research
         as part of a Bona Fide Collaboration, or Eos' research in connection
         with a Not-for-Profit Sample Provider.
2.10     "Fabrication Verification Criteria" shall refer to Affymetrix' then
         current quality control criteria for Probe Arrays that are widely
         distributed to third parties, which quality control criteria as
         presently constituted have been delivered to Eos and which will be
         provided to Eos from time to time when a material change is made.
2.11     "GATC Compliant" shall refer to software and/or databases meeting the
         standards set forth in accordance with the Genetic Analysis Technology
         Consortium ("GATC") standards group. In the event that the GATC
         standards are no longer maintained, the Parties will negotiate in good
         faith to provide substitute specifications for interoperability of
         their respective software and databases.
2.12     "Gene" shall refer to a nucleic acid sequence encoding a distinct RNA.
         A Gene may be represented by a partial nucleic acid sequence
         representing an expressed sequence tag (EST). Multiple ESTs from the
         same Gene are considered a single Gene. Polymorphic variants of a
         nucleic acid sequence are considered a single Gene, provided that such
         polymorphic variants must have at least 99% homology with the
         underlying Gene. If a nucleic acid sequence encodes multiple distinct
         RNAs due to alternative splicing, up to [***] of such alternative
         internal splice variants will not be counted as a distinct Genes, the
         remaining splice variants will be considered distinct Genes.
2.13     "Lot" shall refer to the standard minimum quantities in which Probe
         Arrays are made available to third parties, as set forth in Affymetrix'
         price list and specifications.
2.14     "Net Sales" shall mean the aggregate United States Dollar equivalent of
         gross revenues derived by or payable to Eos or its Affiliates for or on
         account of the transfer, sale, use, license, lease or other disposition
         of Databases to third parties less a) credits or allowances, if any,
         actually granted on account of price adjustments, recalls, rejections,
         or return of items previously sold (but in the aggregate not to exceed
         [***] of gross revenues) b) prompt payment or actual trade or quantity
         discounts actually allowed and taken, or wholesaler chargebacks,
         rebates, or [***] actually given, c) excises, sales taxes,

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         value added taxes, consumption taxes, duties, foreign withholding tax
         actually withheld, or other taxes imposed upon and paid with respect to
         the sale, importation, exportation, transportation, or delivery of
         Databases or services (excluding income taxes of any kind) and d)
         insurance, shipping and delivery costs actually incurred. No deduction
         shall be made for any item of cost incurred by Eos or its Affiliates in
         preparing, manufacturing, shipping, or selling Databases except as
         permitted pursuant to a), b), c) and d) above. Net Sales shall not
         include any transfer between Eos and any of its Affiliates for
         re-license or resale. If Eos or an Affiliate licenses or sells to or
         through a distributor (that is not an Affiliate of Eos), Net Sales
         shall be the gross revenues received by Eos and/or the applicable
         Affiliate from the license of the Database to such distributor. Any
         such distributor arrangement must be under a written agreement
         containing reasonably standard commercial terms. In the event that Eos
         or any of its Affiliates licenses a Database to third parties for [***]
         in whole or in part, such transfer shall be considered a license
         hereunder for accounting and royalty purposes. Net Sales for any such
         transfers shall be determined on a country-by-country basis and shall
         be the average price of [***] licenses by Eos or its Affiliates in such
         country during the royalty reporting period in which such transfer
         occurs, or if no such [***] licensing occurred in such country during
         such period, during the last period in which such [***] sales occurred.
         If no [***] licenses have occurred in a particular country, Net Sales
         for such transfer shall be the average price of [***] licenses in all
         countries. If a Database is sold or licensed as part of a system,
         package, or combination product, Net Sales shall be calculated by
         multiplying the Net Sales of the combination product [***] of the
         combination product. If the Database is not licensed separately as part
         of the combination, the Parties shall agree upon a commercially
         reasonable allocation of the revenue to the Database.
2.15     "Not-for-Profit Sample Providers" shall mean not-for-profit
         institutions or principal investigators at not-for-profit institutions
         i) that own biological samples that are not transferable to Eos by law
         or institutional policy, and ii) to which Eos may provide Expression
         Probe Arrays solely for the purpose of scanning such samples at such
         institution's site and providing the resulting data exclusively to Eos
         for use solely as permitted in this Agreement, and iii) that agree to
         the terms set forth in Exhibit F hereto and iv) whose name and address
         have been provided in writing to Affymetrix, or v) that have been
         approved in advance by Affymetrix in writing which approval shall not
         unreasonably be withheld.
2.16     "Party" shall mean Affymetrix or Eos. "Parties" shall mean Affymetrix
         and Eos.
2.17     "Physical Defects" shall mean defects resulting from the manufacture or
         handling of Probe Arrays by Affymetrix prior to shipment, such that
         such defects are the cause of impaired hybridization of a significant
         number of probe pairs leading to aberrant probe set data for a
         significant number of Genes. Such determination must be made pursuant
         to Affymetrix' then current GeneChip expression assay protocols.
2.18     "Probe Array" shall mean a solid support having an array of
         polynucleotides with known location and sequence fabricated by
         Affymetrix pursuant to this Agreement for use in

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         expression analysis.
2.19     "Probe Selection Methods" shall refer to any methods developed by Eos
         for the selection of probes for Custom Probe Array designs.
2.20     "Proprietary Probe Arrays" shall refer to Probe Arrays which contain
         substantial proprietary genetic information of a third party for which
         incremental fees are due by Affymetrix to such third party associated
         with the use of such proprietary genetic information.
2.21     "Services" shall mean the collection and provision for consideration of
         information derived from a Probe Array to a single third party.
2.22     "System(s)" shall mean fluidics station(s), work station(s), probe
         array reader(s), and associated software, such software licensed to
         Eos, and such fluidics station(s) and probe array reader(s) sold to
         Eos.
2.23     "Term" shall mean the period beginning on the Effective Date and ending
         two(2) years from the Effective Date, unless extended by mutual written
         agreement of the parties or unless i) Eos elects to participate in the
         Affymetrix GOLD EasyAccess Program in which case the Term shall end
         three (3) years from the Effective Date, or ii) the Agreement is
         extended pursuant to Section 10.4. "Initial Term" shall refer to the
         initial 1 year portion of the Term. "Extended Term" shall refer to the
         potential extension of the Term by 2 or 4 years pursuant to Section
         10.4. For any extension of the Term, the applicable maximum number of
         Datapoints in a Demonstration Database shall be negotiated by the
         Parties in good faith.

3        PROBE ARRAY SUPPLY

3.1      Beginning on the Effective Date, Affymetrix will deliver such
         quantities of the appropriate Probe Arrays as specified in a properly
         rendered purchase order and forecast made by Eos in its sole discretion
         pursuant to Section 3.4, or, for the first 3 months of the Term,
         according to a purchase order and forecast previously supplied by Eos
         and attached as Exhibit A. Affymetrix will replace Probe Arrays that
         have Physical Defects.
3.2      Affymetrix shall not be obligated to provide more than [***] probe
         arrays in any one month during the term hereof, but will use
         commercially reasonable efforts to do so if requested by Eos.
3.3      Beginning on the Effective Date and on the first business day of each
         month during the Term of this Agreement, Eos will provide a reasonable,
         good faith forecast of Probe Arrays to be supplied by Affymetrix to Eos
         and its Affiliates during the following 8-month period or the period
         until the end of the Term if less than 8 months (such forecasts to be
         supplied by number of Probe Arrays and part number). The forecast will
         be provided according to a mechanism and on forms to be agreed upon in
         good faith by the Parties. The first and second month of such forecast
         (part number and individual quantity) shall constitute a firm order.
         The subsequent months of such forecast will be for capacity planning
         purposes only, and shall not constitute a firm commitment. Delivery
         times for all products ordered hereunder will be quoted at the time
         Affymetrix receives a firm order for such products. If the number of
         ordered Probe Arrays forecast for a month increases by more than 100%
         from the immediately preceding firm average monthly forecast for the
         trailing three month period,

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         then the number of such Probe Arrays above the 100% increase shall be
         supplied in a reasonable time, but shall not be subject to penalty or
         breach on account of late supply thereof.
3.4      Probe Arrays will be packed in Affymetrix' standard shipping packages
         and shipped to the address specified by Eos. Deliveries will be F.O.B.
         Affymetrix' facility or the facility of its sales representative.
         Affymetrix will ship via a carrier selected by Eos or, if none is
         specified by Eos, Affymetrix will select the carrier. Title and risk of
         loss or damage for deliveries will pass to Eos upon Affymetrix' actual
         delivery of the Probe Arrays to the carrier for shipment to Eos. Eos
         will pay all shipping costs, duties, and sales taxes. Eos will advise
         Affymetrix if insurance is desired on any shipments of Probe Arrays,
         and will reimburse Affymetrix for all such insurance charges.
3.5      As a participant in the SILVER or GOLD programs Eos is entitled to
         purchase standard custom Probe Array design services from Affymetrix at
         substantially reduced prices per design as follows (depending upon
         which program is in effect, SILVER or GOLD, the reader of this
         Agreement should look only at the appropriate parts of any sections
         containing items preceded by "SILVER: or GOLD:"):
         SILVER:  [***] per custom design.
         GOLD:  [***] per custom design.
         This pricing currently permits specifications for arrays of up to [***]
         probes per Probe Array, up to [***] bases, and up to [***] synthesis
         steps ("Custom Probe Array(s)"). Custom Probe Arrays are currently
         available in the following formats and lot sizes:

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                -----------------------------------------------------
                FORMAT           ARRAYS/WAFER        MINIMUM ORDER
                -----------------------------------------------------
                <S>              <C>                 <C>
                Standard         [***]               [***]
                Midi             [***]               [***]
                Mini             [***]               [***]
</Table>

         All Custom Probe Arrays must be ordered and purchased in whole lot
         increments which may change periodically upon reasonable notice from
         Affymetrix. Pricing for Custom Probe Arrays is pursuant to Exhibit B
         attached hereto. Additional specifications are available in the
         Affymetrix Custom Probe Array Design Guide available from Affymetrix.
         Custom Probe Array designs not within the above parameters or those set
         forth in the Custom Probe Array Design Guide will be considered upon
         request, however, the delivery times indicated below shall not apply to
         such Custom Probe Array designs. When ordering Custom Probe Arrays, Eos
         will identify probe sequences for each Custom Probe Array as set forth
         in the Custom Probe Array Design Guide published as of the Effective
         Date, which may be updated periodically by Affymetrix with reasonable
         notice to Eos, or as agreed upon between the parties. If the
         information received by Affymetrix is incomplete, Affymetrix will
         advise Eos of any additional needed information. Upon confirmed receipt
         of complete probe sequences and related information for each Custom
         Probe Array design:
         SILVER: Affymetrix will use reasonable efforts to design, lay out,
         produce masks and manufacture Custom Probe Arrays for the Target
         Sequences according to the schedule

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         quoted to Eos at the time they order such Custom Probe Array Design but
         in any event Affymetrix shall complete such work within not more than
         [***] business days; or
         GOLD: Affymetrix will use commercially reasonable efforts to design,
         lay out, produce masks, and manufacture quarterly at least one Lot each
         of up to two Custom Probe Array designs within the following times from
         Affymetrix' confirmed receipt of complete probe sequence information
         from Eos: (i) within [***] business days for up to [***] custom designs
         in a single calendar quarter; and (ii) for more than [***] custom
         designs in a single calendar quarter, according to the schedule quoted
         to Eos at the time they order such Custom Probe Array designs. In the
         event Eos orders more than one custom design, Affymetrix reserves the
         right to provide the initial Lots of Custom Probe Arrays for each such
         design at separate times, at Affymetrix' sole discretion, subject to
         the maximum time periods described in the previous sentence; in such
         case, the manufacturing priority of the concurrently ordered initial
         Lots may be determined by Eos on a prioritized list at the time orders
         for the designs are placed or, if no such list is submitted, at
         Affymetrix' discretion. In no event shall Affymetrix be obligated to
         supply more than [***] Custom Probe Array designs per year. Delivery
         times for all additional Lots of Custom Probe Arrays ordered pursuant
         to this Agreement will be quoted at the time Affymetrix receives a firm
         order for such products. The term "Target Sequences" refers to a set of
         Gene sequences for which Eos will have Affymetrix make Custom Probe
         Arrays pursuant to this Agreement. Eos shall be fully responsible for
         the Target Sequences, and, except to the extent arising from
         Affymetrix' commercialization of a particular Custom Probe Array
         design, [***].
3.6      Eos may not: 1) transfer the Probe Arrays provided by Affymetrix
         pursuant to this Agreement to third parties other than (i) Affiliates,
         (ii) [***] under the terms set forth in the letter attached hereto as
         Exhibit D, or (iii) to other Not-for Profit Sample Providers; or 2)
         transfer data generated therewith to any third party other than i)
         Affiliates, ii) Bona Fide Collaborators or iii) subscribers to a
         Database who agree to limit further distribution of the data to other
         third parties consistent with the terms contained in Exhibit C; or 3)
         provide services to any third party, other than to Affiliates, using
         the Probe Arrays provided by Affymetrix pursuant to the Agreement
         except as to those Probe Arrays where i) the service recipient agrees
         to limit further distribution of the data to other third parties
         consistent with the terms contained in Exhibit C, and ii) the fee for
         Probe Arrays used in Services is paid pursuant to Section 5.3; or 4)
         allow any third party to use the Probe Arrays supplied by Affymetrix to
         Eos under this Agreement except pursuant to subsection 1) above; or 5)
         reverse engineer the Probe Arrays or Systems; or 6) reuse the Probe
         Arrays; or 7) use the Probe Arrays in diagnostic or other settings
         requiring FDA or other regulatory agency approval unless Eos obtains
         such approval and such Probe Arrays are to be used in a clinical trial
         (and such Probe Arrays are not for microbial or pathogenic organisms).
         Eos will allow Affymetrix reasonable, periodic (but not more often than
         quarterly) access to the Systems during regular business hours and with
         advance written notice to ensure compliance with the prohibition
         against reuse.

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3.7      All Databases transferred to a third party by Eos pursuant to this
         Agreement must be GATC Compliant and shall be subject to the terms
         contained in Exhibit C. Eos will bear its internal costs of GATC
         compliance.
3.8      Eos may not sell, market or license the Databases through a distributor
         or agent unless such distributor or agent is approved in advance in
         writing by Affymetrix.
3.9      Eos may, in its sole discretion, elect to engage Affymetrix as a
         co-promoter of the Databases generated hereunder. If Eos makes such an
         election, and if Affymetrix agrees to such co-promotion, the parties
         will negotiate a commercially reasonable co-promotion agreement.
3.10     Eos agrees to use Affymetrix' GeneChip logo on all advertising
         (including web advertising) and trade show displays related to
         Databases and/or Services, unless such use is terminated pursuant to
         the last sentence of this Section 3.10. All advertising and trade show
         displays based on Affymetrix products and written public statements
         regarding Affymetrix and Affymetrix products will be approved in
         advance in writing by Affymetrix. Eos acknowledges the ownership and
         renown of all trademarks, logos and tradenames ("Marks") used by
         Affymetrix prior to this agreement. Eos will maintain a high quality
         standard in connection with products and services promoted in
         connection with Affymetrix' Marks. Eos hereby authorizes Affymetrix to
         use Eos' name and trademarks for the purpose of promoting Affymetrix'
         products and services, but Affymetrix may not do so without Eos' prior
         written consent. If, in each party's sole discretion, the other party's
         use of the first party's Marks does not meet the first party's usage
         policy, the first party may, at its option, terminate the other party's
         use of the first party's Marks.

4        AFFYMETRIX PROPRIETARY RIGHTS

4.1      GOLD: Until the end of the Term, Eos will not buy arrays of diverse
         nucleic acids on solid supports from a third party when such third
         party arrays materially infringes or would materially infringe the
         patent or copyright rights of Affymetrix or its Affiliates. In order to
         enforce this provision Affymetrix must provide Eos a) reasonable and
         prompt written notice of such infringement upon Affymetrix becoming
         aware of such infringement, and b) reasonable evidence of such
         infringement, with which counsel for Eos reasonably concurs. This
         paragraph shall not confer on Eos or any third party any rights under
         the patent rights of Affymetrix.

5        COMPENSATION

5.1      In exchange for preferential access and pricing of Custom Array design
         services, database and other licenses, technology access, services and
         other support available to Eos under the SILVER program, Eos shall pay
         Affymetrix a fee of [***] per year ("Silver Access Fee") due on the
         Effective Date and on the anniversary of the Effective Date for each
         contract year throughout the Term (and any Extended Term). Eos shall
         have the option during the initial contract year to upgrade to the GOLD
         EasyAccess program and apply the Silver Access Fee paid to Affymetrix
         to the GOLD Access Fee for the remainder of the

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         current contract year.
         GOLD: If Eos chooses to upgrade its package to GOLD, Eos shall pay
         Affymetrix a fee of [***] ("Gold Access Fee") per year beginning on the
         date Eos elects in writing to begin the GOLD program ("GOLD Start
         Date") on the following payment schedule: [***] due on GOLD Start Date
         and [***] at the end of every three (3) month period thereafter
         throughout the remainder of the Term or Extended Term after the GOLD
         Start Date (and any Extended Term). If Eos chooses to upgrade its
         package to GOLD within twelve (12) months of the Effective Date, the
         remaining pro-rata portion of the Silver Access Fee paid under the
         SILVER package shall be applied to the first Gold Access Fee payment
         due after the GOLD Start Date.
5.2      For each standard expression Probe Array and Custom Expression Probe
         Array (excluding those Probe Arrays for use in Services) delivered to
         Eos or its Affiliates that meet the Fabrication Verification Criteria,
         Eos will pay:
         SILVER:
                  (i) Arrays for Database generation: Eos will pay [***] of
                  Affymetrix' current published regional list prices, which may
                  be updated periodically, for (i) standard Probe Arrays that
                  Affymetrix makes generally available to the public (excluding
                  Test Arrays and those Probe Arrays for use in Services),
                  provided that Eos will be responsible for the full amount of
                  any royalties due to third parties for "branded" probe arrays
                  that are based on such third party's proprietary genetic
                  sequences and (ii) Custom Probe Arrays, excluding those Custom
                  Probe Arrays for use in Services. The list prices for Custom
                  Probe Arrays shall be pursuant to Exhibit B. In no event shall
                  the foregoing pricing reduce the price of any expression probe
                  array to less than [***] per array ("Database Array Price").

                  (ii) Arrays for Expression Research: Eos will pay [***] of
                  Affymetrix' current published regional list prices, which may
                  be updated periodically, for (i) standard Probe Arrays that
                  Affymetrix makes generally available to the public (excluding
                  Test Arrays and those Probe Arrays for use in Services),
                  provided that Eos will be responsible for the full amount of
                  any royalties due to third parties for "branded" probe arrays
                  that are based on such third party's proprietary genetic
                  sequences; and (ii) Custom Probe Arrays, excluding those
                  Custom Probe Arrays for use in Services. The list prices for
                  Custom Probe Arrays shall be pursuant to Exhibit B. In no
                  event shall the foregoing pricing reduce the price of any
                  expression probe array to less than [***] per array.

                  The above notwithstanding, during each contract year, after
                  Eos purchases a total of [***] Probe Arrays and Custom Probe
                  Arrays, excluding Test arrays and Probe arrays priced below
                  [***] per array, for use in Database generation and Expression
                  Research, the price for arrays used in Expression Research for
                  the remainder of such contract year shall be:

                     (a) [***] for Probe Arrays that Affymetrix makes generally
                     available to the

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -9-
<Page>

                     public

                     (b) the greater of [***] of list price or [***] for
                  Custom Probe Arrays ("Expression Research Array Price").
                  All Eos purchase orders shall state the use of Probe Arrays
                  ordered: Database, Expression Research, or Services.

                  (iii) Eos shall purchase all Probe Arrays and Custom Probe
                  Arrays at the Database Array Price, Eos may submit to
                  Affymetrix on a quarterly basis a completed, signed Request
                  For Credit Form, attached hereto as Exhibit F, resulting from
                  Probe Arrays and Custom Probe Arrays used during the previous
                  quarter for Expression Research that were purchased at the
                  Database Array Price. Such credit shall be calculated as
                  follows:

                  [***]

                  Such credit shall be (i) requested within thirty (30) days
                  after the last day of each calendar quarter for the previous
                  quarter's purchases, (ii) applicable only toward future
                  purchases of Probe Arrays or Custom Probe Arrays and (iii)
                  applied to no greater than [***] of the total array cost on
                  any single order.

         GOLD: a fixed fee of the greater of: [***] of Affymetrix' then-current
         regional list price as published in its catalog, which may be updated
         from time to time; or, [***] (current list prices for Custom Probe
         Arrays are stated in Exhibit B attached hereto, excluding those Custom
         Probe Arrays for use in Services), provided that Eos will be
         responsible for the full amount of any royalties due to third parties
         for "branded" probe arrays that are based on such third party's
         proprietary genetic sequences.

5.3      For each Probe Array to be used in Services delivered to Eos or its
         Affiliates that meets the Fabrication Verification Criteria, Eos shall
         pay [***] of Affymetrix' then current local (relative to the country in
         which the data from such Service is to be utilized) list price as
         published in its catalog or, if applicable, the price then available to
         that particular third party recipient of such Services (if lower). As
         to third parties who benefit from such lower prices, such third party
         shall place a purchase order directly with Affymetrix for probe arrays
         to be shipped directly to Eos and used in Services and will be invoiced
         directly by Affymetrix. Eos may not provide services to any third
         party, other than to Affiliates, using the Custom Probe Arrays provided
         by Affymetrix hereunder except as to those Custom Probe Arrays where i)
         the service recipient is a paying Database subscriber who agrees to
         limit further distribution of the data to other third parties
         consistent with the terms contained in Exhibit C, ii) the service
         recipient agrees to limit further distribution of the data to other
         third parties consistent with Affymetrix' normal Expression Probe Array
         use rights attached hereto as Exhibit C, and iii) the fee for Custom
         Probe Arrays used in Services is paid as set forth

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -10-
<Page>

         herein.
5.4      Notwithstanding the foregoing or any provision to the contrary in this
         Agreement, Eos will be responsible for the full amount of any and all
         royalties due to third parties for proprietary Probe Arrays supplied to
         Eos hereunder, and the Probe Array fees and Database royalties
         described in this Agreement shall be exclusive of any such royalty.
5.5      At the time and in the manner hereinafter provided, Eos shall pay to
         Affymetrix a royalty of [***] of Net Sales for each transfer, sale,
         use, license, lease or other disposition of a Database to a third
         party; provided, however, that with respect to each such license, the
         minimum royalty payable for each successive 12-month period commencing
         with the inception of such license shall be calculated according to the
         following schedule:

<Table>
<Caption>
                          For Sale of Databases Comprised of *
         --------------------------------- ------- ------------------------------ ----------------------------
         More Than                          But    No More Than                        Minimum Annual Royalty
         --------------------------------- ------- ------------------------------ ----------------------------
         <S>                                       <C>                            <C>
         [***] Datapoints                          The then applicable                                  [***]
                                                   maximum number of
                                                   Datapoints for a
                                                   Demonstration Database
                                                   but not fewer than [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         The then applicable                       [***] Datapoints                                     [***]
         maximum number of
         Datapoints for a
         Demonstration Database
         but not fewer than [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                          [***] Datapoints                                     [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                          [***] Datapoints                                     [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                          [***] Datapoints                                     [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                          [***] Datapoints                                     [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                          [***] Datapoints                                     [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                          [***] Datapoints                                     [***]
         --------------------------------- ------- ------------------------------ ----------------------------
         [***] Datapoints                                                         For Databases comprised of
                                                                                  more than [***] Datapoints,
                                                                                  the Parties shall negotiate in
                                                                                  good faith a minimum annual
                                                                                  royalty.

         --------------------------------- ------- ------------------------------ ----------------------------
</Table>

         *For purposes of calculating the minimum annual royalty, the size of
         the Database will be measured by the

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -11-
<Page>

         number of Datapoints. [***]

5.6      Except as to Database royalty payments, all amounts referred to in this
         Section 5 will be invoiced by Affymetrix when due. Royalty payments
         will be due as specified in Section 5.7. All Probe Arrays will be
         deemed accepted unless they are returned to Affymetrix within 45 days
         of delivery to Eos, with written explanation of the basis on which such
         Probe Arrays have been returned on Affymetrix' standard "Return
         Materials Authorization" according to the procedures provided for in
         such Return Materials Authorization. All payments will be made to
         Affymetrix within thirty (30) days from the date of invoicing by
         Affymetrix. Late payments shall bear interest at the rate of 1.5% per
         month. All payments in this Agreement will be made in the form of a
         check or wire transfer to Affymetrix in U.S. Dollars.
5.7      Eos shall deliver to Affymetrix, within forty-five (45) days after the
         end of each calendar quarter, a written report showing its computation
         of payments due under Section 5 of this Agreement, including any Net
         Sales of licenses of Databases by Eos or its Affiliates during such
         calendar quarter. All Net Sales shall be segmented in each such report
         according to licenses by Eos and each Affiliate on a country by country
         basis, including the names and terms extended to the licensee and the
         rates of exchange used to convert such royalties to U.S. Dollars from
         the currency in which the licenses were made. For the purposes of this
         Agreement, the rates of exchange to be used for converting royalties to
         U.S. Dollars shall be the average of those published for the purchase
         of U.S. Dollars in the Wall Street Journal during the calendar quarter
         for which payment is due. Simultaneously with the delivery of each such
         report, Eos shall tender payment in U.S. Dollars of all royalties shown
         to be due therein. Where royalties are due for licenses of Databases in
         a country where, by reason of currency regulations it is impossible or
         illegal for Eos or its Affiliates to transfer royalty payments to
         Affymetrix, such royalties shall be deposited in whatever currency is
         allowable in a bank in that country that is reasonably acceptable to
         Affymetrix. Any and all income or similar taxes imposed or levied on
         account of the receipt of royalties payable under this Agreement which
         are required to be withheld by Eos shall be paid by Eos on behalf of
         Affymetrix and shall be paid to the proper taxing authority. Proof of
         payment shall be secured and sent to Affymetrix as evidence of such
         payment in such form as required by the tax authorities having
         jurisdiction over Eos or its Affiliates. Such taxes shall be deducted
         from the royalty that would otherwise be remitted by Eos or its
         Affiliates.

5.8      Systems and other software, if any, may be acquired/licensed by Eos and
         its Affiliates at Affymetrix' regional list prices and under otherwise
         standard terms.
5.9      Eos may purchase LIMS and EDMT software as follows:
         SILVER: [***] of Affymetrix' then current regional list prices as
         published in its catalog;
              or
         GOLD: [***] of Affymetrix' then current regional list prices as
         published in its catalog.
5.10     GOLD: Affymetrix will provide early access to new product releases to
         Eos in a manner consistent with its Easy Access "Gold" customers.

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -12-
<Page>

5.11     Following Eos' request, Affymetrix agrees to supply to Eos during the
         Term Custom Probe Arrays to be used by Eos in generating Databases or
         providing Services.
5.12     Eos may only provide services hereunder to its customers located in
         the United States and Europe.

6        INTELLECTUAL PROPERTY

6.1      Subject to Section 6.2 below, any invention made during the course of
         and as part of this Agreement shall be owned according to inventorship
         of the relevant applications, provided that Eos (and its Affiliates)
         agree to assign to Affymetrix at Affymetrix' cost all [***]. Eos agrees
         to communicate periodically [***] to Affymetrix. Affymetrix hereby
         grants to Eos and its Affiliates a non-sublicensable, royalty free
         license to use such [***] for internal research purposes only.
6.2      Eos agrees that at its sole discretion Eos may choose not to disclose
         any [***] to Affymetrix and whether such [***] shall be considered Eos'
         Confidential Information. If Eos elects at its sole discretion to allow
         Affymetrix to patent any [***], such [***]shall be conclusively deemed
         a [***] and subject to the terms of Section 6.1 above. Notwithstanding
         the foregoing, EOS shall not [***] and, except as otherwise provided
         herein, shall maintain such [***]. If at any time any [***] is not
         maintained by Eos as a [***], such [***] shall be conclusively deemed a
         [***] and subject to the terms of Section 6.1 above. It is specifically
         understood that limited and recoverable disclosures of Confidential
         Information shall not constitute failure to maintain information as a
         trade secret pursuant to this Section 6.2.
6.3      EOS agrees to negotiate in good faith with Affymetrix for at least a
         non-exclusive license with commercially reasonable terms and conditions
         solely in the probe array field of use under all Eos owned inventions
         that are directed to particular genetic sequences or their uses that
         were discovered through use of the Probe Arrays. Such license will be
         negotiated to include commercially reasonable royalty payments, and
         need only be provided if legally licensable at the time the invention
         is made. Eos need not disclose such inventions to Affymetrix until such
         time as corresponding patents are published disclosing such inventions.
6.4      Eos will reasonably provide recognition of Affymetrix by way of display
         of its trademarks in its database products generated pursuant to this
         Agreement. Affymetrix grants Eos a non-exclusive right to use its
         trademarks subject to written approval of Affymetrix on such products.
         Eos will allow Affymetrix reasonable review of the use of such
         trademarks.
6.5      At Affymetrix' request, Eos shall negotiate in good faith for
         non-exclusive, non-sublicensable, non-transferable access to Affymetrix
         under reasonable terms and conditions to Eos' [***] including without
         limitation [***]; such access will be granted at least in the field of
         [***] and shall be on terms,

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -13-
<Page>

         including royalty and other price terms, no less favorable than those
         granted to [***].

7        CONFIDENTIALITY

7.1      During the term of this Agreement and for five (5) years thereafter
         each Party shall maintain the Confidential Information of the other
         Party in confidence (including the terms of this Agreement), and shall
         not disclose, divulge, or otherwise communicate such Confidential
         Information of the other, or use it for any purpose, except as
         permitted or contemplated by this Agreement, and in order to carry out
         the terms and objectives of this Agreement. The Parties will use
         reasonable precautions to prevent and restrain the unauthorized
         disclosure of such Confidential Information of the other Party and will
         protect such other party's confidential information with procedures at
         least as rigorous as those the receiving party applies to its own
         confidential information. The provisions of this paragraph shall not
         apply to Confidential Information that :
7.1.1    was known or used by the receiving Party or its Affiliates without any
         restriction on disclosure, prior to its date of disclosure to the
         receiving Party, as evidenced by the prior written records of the
         receiving Party or its Affiliates; or
7.1.2    either before or after the date of the disclosure to the receiving
         Party is lawfully disclosed without restriction on disclosure to the
         receiving Party or its Affiliates by an independent, unaffiliated third
         party rightfully in possession of the Confidential Information,
         provided that if such Confidential Information is provided to the
         receiving Party by a third party rightfully in possession of the
         Confidential Information, but with restrictions on disclosure, the
         receiving Party may use such Confidential Information in accordance
         with such restrictions of the third party;
7.1.3    either before or after the date of the disclosure to the receiving
         Party such Confidential Information becomes published or generally
         known to the public through no fault or omission of the receiving Party
         or its Affiliates;
7.1.4    is required to be disclosed by the receiving Party or its Affiliates to
         comply with applicable laws, to comply with a court order, or to comply
         with governmental regulations, provided that the receiving Party
         provides prior written notice of such disclosure to the other Party and
         takes reasonable and lawful actions to avoid and/or minimize the degree
         of such disclosure;
7.1.5    is independently developed by the receiving Party or its Affiliates
         without reference to the Confidential Information.
7.1.6    Eos may not publish the results of use of the Probe Arrays without
         providing reasonable advance notice to Affymetrix. In no event shall
         Eos publish Affymetrix' Confidential Information (including without
         limitation Chip Improvement Inventions) without prior written approval
         of Affymetrix.

8        WARRANTY

8.1      Both Parties to this Agreement represent and warrant that they have the
         full right and

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -14-
<Page>

         authority to enter into and perform this Agreement.
8.2      Affymetrix warrants that the Probe Arrays delivered hereunder do not
         incorporate the trade secret or copyright rights of a third party.
         Affymetrix DISCLAIMS ALL OTHER REPRESENTATIONS AND WARRANTIES, EXPRESS
         OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
         RELATING TO INTELLECTUAL PROPERTY, MERCHANTABILITY, AND FITNESS FOR A
         PARTICULAR PURPOSE. Affymetrix shall have no liability under any theory
         of strict liability, negligence, whether active or passive, or products
         liability. Affymetrix' entire liability shall in no event exceed the
         compensation hereunder. Affymetrix shall have no liability for any
         indirect, consequential, incidental, or special damages. Eos
         understands that the risks of loss herein are reflected in the price of
         the Probe Arrays and database fees and that the terms would have been
         different if there had been a different allocation of risk.

9        INDEMNITY

9.1      Affymetrix will settle or defend any suit or proceeding brought against
         Eos and its Affiliates to the extent based on a claim that the Probe
         Arrays delivered hereunder directly infringe an issued patent in the
         United States of America, Europe and Japan. Affymetrix will settle or
         defend any suit or proceeding brought against Eos to the extent based
         on a claim that the Probe Arrays delivered hereunder indirectly (i.e.
         through contributory infringement or inducement) infringe an issued
         patent in the United States of America if a) a hybridization method
         using probe arrays, or probe arrays themselves, or equivalent
         hybridization devices are specifically identified as an element of the
         claims of such patent in a device claim, or use of these is
         specifically identified as an element of the claims of such patent in a
         method claim, and b) the patentability of such device or method claims
         was materially related to the recitation of the hybridization method or
         the probe arrays or equivalent hybridization device, or their use.
         Affymetrix shall have no liability under this paragraph to the extent
         that the alleged infringement arises out of any addition or
         modification to the Probe Arrays or their use by Eos not specified by
         Affymetrix, or Eos' combination of the Probe Arrays with other devices
         not specified by Affymetrix ("Non-Covered Claims)."
9.2      Eos will settle or defend any suit or proceeding based on an issued
         patent in the United States of America, Europe or Japan brought against
         Affymetrix for Non-Covered Claims.
9.3      The indemnifying Party shall pay all damages and costs finally awarded
         against the indemnified Party for such infringement. For the
         indemnification obligations of this Section 9 to apply the indemnified
         Party must provide the indemnifying Party with reasonable notice of any
         claim or suit being made or brought, and give the indemnifying Party
         the full authority, information, and assistance necessary to settle or
         defend such suit or proceeding. The indemnifying Party shall not be
         bound in any manner by any settlement made without its prior written
         consent. Each party's liability hereunder shall be limited to [***]. In
         the event that the Probe Arrays are held to infringe and their use is
         enjoined as a result of infringement for which it has indemnified Eos,
         Affymetrix may obtain for Eos the right to continue using such

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -15-
<Page>

9.4      Probe Arrays, modify them to become non-infringing, or grant Eos a
         credit for the cost of unused Probe Arrays and the appropriate pro rata
         amount of the paid SILVER or GOLD access fee, and accept the return of
         unused Probe Arrays. This paragraph states the entire liability for
         infringement of intellectual property rights and is in lieu of all
         other warranties, express or implied except as stated in Section 8.

10       TERM, TERMINATION AND EFFECT OF TERMINATION

10.1     This Agreement shall extend until the end of the Term unless terminated
         earlier by a Party pursuant to the provisions of this Section 10.
10.2     Either Party may terminate this Agreement for cause by written notice
         if the other Party (or its Affiliate) materially breaches any material
         provision of this Agreement and fails to substantially cure such breach
         within thirty (30) days of written notice describing the breach and the
         intent of the notifying Party to terminate the Agreement in the event
         such breach is not substantially cured.
10.3     Eos may terminate the Database or Services portions of this Agreement
         in the event that Eos determines in its sole discretion that Eos no
         longer wishes to engage in the Database or Services Business. Such
         termination may be effected by Eos providing sixty (60) days prior
         written notice to Affymetrix. If Eos elects to terminate under this
         Section 10.3, Eos' obligation to pay royalties for a Database (other
         than the obligation to pay a minimum annual royalty pursuant to Section
         5.5 above, which shall not survive) shall survive termination of this
         Agreement and persist as long as any third party retains an active
         subscription to such Database.
10.4     GOLD: Eos may extend the Term by two (2) years by providing written
         notice to Affymetrix no later than ninety (90) days before the end of
         the Initial Term. If so extended for two (2) years, Affymetrix will
         negotiate in good faith for an additional extension of the Term of the
         Agreement under similar terms for an additional two (2) years (for a
         potential Term of up to seven (7) years), provided that Eos must
         provide at least one hundred eighty (180) days written notice before
         the end of the initial Extended Term of its desire to negotiate in good
         faith for such extension.
10.5     Upon termination of this Agreement due to expiration of the Term, Eos
         may continue to use the Probe Arrays previously purchased by Eos within
         their specified shelf life and subject to the warranty and return
         provisions provided in this Agreement.
10.6     Eos understands that no license is conveyed or implied for use of the
         Systems herein for probe arrays other than those manufactured or
         licensed by Affymetrix.
10.7     Upon termination of this Agreement, the following provisions will
         survive: 2, 3.6, 3.8, 3.9, 5.2*, 5.3*, 5.4, 5.5**, 5.6, 5.7, 6, 8, 9,
         10.5, 10.6, 10.7, and 11.1 to11.17. (*To the extent obligations are
         accrued prior to the termination date.) (**Eos' obligation to pay
         royalties for a Database shall survive termination of this Agreement
         and persist as long as any third party retains an active subscription
         to such Database.)

CONFIDENTIAL

                                      -16-
<Page>

11       MISCELLANEOUS

11.1     Eos shall keep, and shall cause its Affiliates to keep, for a period of
         at least three (3) years from the date all fees and royalties payable
         hereunder are due full, accurate, and true books of accounts and other
         records containing all information and data which may be reasonably
         necessary to ascertain and verify i) the fees and royalties payable
         hereunder and, ii) if relevant pursuant to Section 5.2(ii) above, the
         quantities of Probe Arrays and Custom Probe Arrays used for Database
         generation and Expression Research and iii) the quantities of Probe
         Arrays and Custom Probe Arrays used for Database generation and
         Services. During the Term and any Extended Term of this Agreement and
         for a period of two (2) years following the time at which the relevant
         fee or payment is due, Affymetrix shall have the right from time to
         time (not to exceed once during a calendar year) to inspect in
         confidence, or have an agent, accountant, or representative inspect in
         confidence such books, records, and supporting data. In the event an
         audit reveals a discrepancy greater than 5% in the relevant period, Eos
         will pay any audit fees.
11.2     EOS UNDERSTANDS THAT THE PROBE ARRAYS DELIVERED HEREUNDER ARE NOT FDA
         APPROVED. EOS AGREES NOT TO USE THE PROBE ARRAYS DELIVERED HEREUNDER IN
         ANY CLINICAL OR OTHER SETTING REQUIRING FDA REVIEW OR APPROVAL EXCEPT
         THAT EOS MAY USE THE PROBE ARRAYS IN CLINICAL TRIALS WHEN IT OBTAINS
         ALL REQUIRED FDA OR OTHER REGULATORY APPROVALS REQUIRED FOR USE IN SUCH
         TRIALS. EOS WILL INDEMNIFY AFFYMETRIX FOR ANY CLAIMS MADE BY A PATIENT
         ARISING FROM THE USE OF THE PROBE ARRAYS. THE PROBE ARRAYS AND SYSTEMS
         ARE NOT LICENSED UNDER ANY INTELLECTUAL PROPERTY RIGHTS OF AFFYMETRIX
         EXCEPT AS SPECIFICALLY RECITED HEREIN.
11.3     Neither Party nor any of its Affiliates shall originate any news
         relating to this Agreement without the prior written approval of the
         other Party, which approval shall not be unreasonably withheld, or
         except as otherwise required by law.
11.4     The parties seek mutually profitable arrangements and to such end will
         endeavor to mutually support each other in public statements.
11.5     Affymetrix may assign any rights or obligations of this Agreement to a
         third party that acquires all or substantially all of the relevant
         assets of Affymetrix by merger or sale of assets or otherwise. Eos may
         assign the rights or obligations of this Agreement relating solely to
         purchase of Probe Arrays from Affymetrix for Expression Research only
         to a third party that acquires all or substantially all of the Eos'
         assets by merger or sale of assets or otherwise except where the
         assignee is a company or an Affiliate of a company that is at the time
         of assignment a party or an Affiliate of a party to litigation with
         Affymetrix or its Affiliate, in which case Affymetrix may withhold
         consent for any reason or no reason in Affymetrix' absolute sole
         discretion. Eos may assign or transfer any Database distribution or
         Services rights or any Database distribution or Services obligations of
         this Agreement by merger or sale of assets or otherwise to a third
         party or its Affiliates only with the prior written consent of
         Affymetrix which must be obtained and will not be unreasonably

CONFIDENTIAL

                                      -17-
<Page>

         withheld, except where the assignee is a company or an Affiliate of a
         company that has significant commercial sale or commercial
         manufacturing of nucleic acid arrays or engages in significant research
         and development activities toward commercial sale or commercial
         manufacturing of nucleic acid arrays (including, without limitation,
         [***] or their Affiliates, assigns or successors in interest) or is at
         the time of assignment a party or an Affiliate of a party to litigation
         with Affymetrix or its Affiliate, in which case Affymetrix may withhold
         consent for any reason or no reason in Affymetrix' absolute sole
         discretion.
11.6     In the event that Eos merges with, acquires or is acquired by any third
         party such that demand for products hereunder more than triples over
         the previous calendar quarter, then the parties shall negotiate revised
         pricing and terms that reflect such increased demand, and Affymetrix'
         costs, if any, in providing products and support hereunder. If Eos
         elects to participate in the Affymetrix GOLD EasyAccess Program and Eos
         merges with or is acquired by a third party that also pays to
         Affymetrix GOLD Database Fees, the parties agree that the aggregate
         amount of GOLD Database Fees paid to Affymetrix by the combined entity
         shall be as follows:

<Table>
<Caption>
--------------------------------------------------------------------------
Quarter after merger or               Percent of Eos' GOLD Database Fees
acquisition is completed              paid to Affymetrix by the combined
                                      entity
--------------------------------------------------------------------------
         <S>                                         <C>
          first                                      [***]
--------------------------------------------------------------------------
         second                                      [***]
--------------------------------------------------------------------------
          third                                      [***]
--------------------------------------------------------------------------
         fourth                                      [***]
--------------------------------------------------------------------------
</Table>

11.7     This Agreement  shall be construed  according to the laws of California
         without regard to conflict of law provisions.
11.8     In the event of any controversy or claim relating to, arising out of or
         in any way connected to any provision of this Agreement, the Parties
         shall seek to settle their differences amicably between themselves.
11.9     The waiver by either Party of a breach or a default of any provision of
         this Agreement by the other Party shall not be construed as a waiver of
         any succeeding breach of the same or any other provision, nor shall any
         delay or omission on the part of either Party to exercise or avail
         itself of any right power or privilege that it has or may have
         hereunder operate as a waiver of any right, power or privilege by such
         Party.
11.10    This Agreement and the documents referred to herein are the full
         understanding of the Parties with respect to the subject matter hereof
         and supersede all prior understandings and writings relating to the
         subject matter herein. No waiver alteration or modification of any of
         the

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -18-
<Page>

         provisions herein shall be binding unless in writing and signed by the
         Parties.
11.11    The headings in this Agreement are for convenience only and shall not
         be considered in construing this Agreement.
11.12    In the event that any provision of this Agreement is held by a court of
         competent jurisdiction to be unenforceable because it is invalid or in
         conflict with any law of any relevant jurisdiction, the validity of the
         remaining provisions shall not be affected, and the rights and
         obligations of the Parties shall be construed and enforced as if the
         Agreement did not contain the particular provision(s) held to be
         unenforceable.
11.13    This Agreement shall be binding on and inure to the benefit of the
         Parties and their successors and permitted assigns.
11.14    None of the provisions of this Agreement shall be for the benefit of or
         enforceable by any third party.
11.15    Any notice required under this Agreement shall be made by overnight
         mail or courier to the addresses below.

         If to Eos:

                  Eos Biotechnology, Inc.
                  225A Gateway Boulevard
                  South San Francisco, CA 94080
                  Attn: President
                  Facsimile Number: 650-583-3881

         If to Affymetrix:

                  Affymetrix, Inc.
                  3380 Central Expressway
                  Santa Clara, California 95051
                  Attn: General Counsel
                  Facsimile Number: (408) 731-5394

11.16    "Force Majeure" shall mean an Act of God, flood, fire, explosion,
         earthquake, strike, lockout, casualty or accident, war, civil
         commotion, act of public enemies, blockage or embargo, or any
         injunction, law, order proclamation, regulation, ordinance, demand or
         requirement of any government or any subdivision, authority
         representative thereof, or the inability to procure or use materials,
         labor, equipment, transportation or energy sufficient to meet
         manufacturing needs without the necessity of allocation, or any other
         cause whatsoever, whether similar or dissimilar to those enumerated
         above, which is beyond the reasonable control of such Party, which the
         party affected has used its reasonable best efforts to avoid, and which
         prevent, restrict or interfere with the performance by a Party of its
         obligations hereunder. The failure of either Party to timely perform
         any obligation under this Agreement as a direct result of a Force
         Majeure shall not be deemed a material breach of this Agreement,
         provided the duration is not more than three months. The Party affected
         by Force Majeure shall give

CONFIDENTIAL

                                      -19-
<Page>

         notice to the other Party promptly in writing and shall use
         commercially reasonable efforts to overcome, avoid or remove such
         cause(s) of non-performance and shall continue performance whenever
         such cause(s) is removed with all possible speed. Nothing herein shall
         be deemed to require any Party to settle on terms unsatisfactory to
         such Party with regard to any strike, lockout or other labor
         difficulty, any investigation or proceeding by any public authority or
         any litigation by any third party.
11.17    This Agreement may be executed in any number of counterparts, each of
         which shall be deemed an original but all of which together shall
         constitute one and the same instrument.

IN WITNESS WHEREOF, the Parties hereto have caused this Agreement to be executed
by their properly and duly authorized officers or representatives as set forth
below.

Affymetrix, Inc.

By:      /s/ Susan E. Siegel
    --------------------------------

Name:    Susan E. Siegel
      ------------------------------

Title:   PRESIDENT
       -----------------------------

Date:    8/17/01
      ------------------------------


Eos Biotechnology, Inc.

By:      /s/ David W. Martin, Jr.
    --------------------------------

Name:    David W. Martin, Jr.
      ------------------------------

Title:   President and CEO
       -----------------------------

Date:    8/17/01
      ------------------------------

CONFIDENTIAL

                                      -20-
<Page>

                                    EXHIBIT A
                                Initial Forecast

CONFIDENTIAL

                                      -21-
<Page>

                                    EXHIBIT B
                       CURRENT CUSTOM PROBE ARRAY PRICING

            For arrays with
            [***] genes      [***] / array
            [***] genes      [***] / array
            [***] genes      [***] / array
            [***] genes      [***] / array
            [***] genes      [***] / array

[***] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.

CONFIDENTIAL

                                      -22-
<Page>

                                    EXHIBIT C
            Expression Probe Array Use Rights for Service Recipients
                            and Database Subscribers

RESTRICTED USE RIGHTS- Purchasers of Services or Database subscribers pursuant
to this Agreement ("Buyer") may only use the data from Expression Probe Array
services provided hereunder to identify the presence and/or levels of expressed
nucleic acid sequences in the ordinary course of Buyer's normal internal
pharmaceutical and diagnostic research and development activities, including
clinical trials. In addition, except to the extent permitted by applicable law
and solely for the purpose(s) contemplated by such law, Buyer agrees not to (a)
provide services to or on behalf of any third party that relate to an Expression
Probe Array; (b) distribute, transfer, license or otherwise make available to a
third party any data or database that is obtained from the use of an Expression
Probe Array; (c) use data from an Expression Probe Array in a clinical
diagnostic setting where data from an identifiable individual's sample is given
to such individual or their caregiver.

Notwithstanding the foregoing, Buyer may: (i) license data obtained from the
Expression Probe Arrays to a third party licensee specifically related to a
particular drug or target that has been discovered through use of the Expression
Probe Arrays when such third party licensee will complete development of,
market, sell and/or distribute such drug or target or collaborate with Buyer to
do the same, (ii) transfer data within a bona fide collaboration in which
Buyer's collaborator has provided substantial scientific input to experimental
design and such relationship is set forth in an agreement signed by all parties
prior to the use of any Expression Probe Arrays to generate such data (bona fide
collaborations do not include arrangements whose primary purpose is to give a
third party access to data or databases or provide nucleic acid hybridization
services), ; (iii) transfer data to a third party so long as Buyer receives no
consideration for such transfer , or (iv) publish data as part of a normal, peer
reviewed scientific publication or public scientific presentation. Buyer agrees
that third parties may only receive data from Expression Probe Arrays under
(i)-(iv) above pursuant to written agreements containing obligations explicitly
benefiting AFX that are no less restrictive than those in this Agreement and
which require such third party recipients not to sublicense or further
distribute or transfer such data (except as necessary in conjunction with the
distribution of a particular drug or target as described in (w) above and
provided that each sublicensee is under obligations consistent with those
contained in this Agreement). In the event of any ambiguity in applying this
Section, the burden shall be on Buyer to reasonably demonstrate compliance with
the terms herein.

CONFIDENTIAL

                                      -23-
<Page>

                                    EXHIBIT D

                                           [EOS BIOTECHNOLOGY LETTERHEAD]


                                                         Eos Biotechnology, Inc.
                                                          225A Gateway Boulevard
                                      South San Francisco, California 94080-7018
                                                                    650/246-2300
                                                               fax: 650/583-3881
                                                              www.eosbiotech.com


June 23, 2000

Ms. Susan E. Siegel
President
Affymetrix, Inc.
3380 Central Expressway
Santa Clara, CA 95051

RE:  COLLABORATION AGREEMENTS

Dear Sue:

Per the instruction of Dawn Kerber of Affymetrix, Inc. ("Affymetrix"), I write
with regard to collaboration agreements into which Eos Biotechnology, Inc.
("Eos") seeks to enter. Ms. Kerber and Mr. Stephen Moore of Affymetrix are both
familiar with the nature of these collaborations, which require us for various
reasons to transfer Affymetrix GeneChips(R) to third parties (the collaborators)
for work to be performed in the course of the collaboration.

This letter is to certify that per the instruction of Affymetrix, we have built
provisions into the collaboration agreements that make clear that the
collaborators agree to be bound by the terms and conditions set forth in the
Chip Supply Agreement executed by Affymetrix and Eos on April 16, 1998. That
Chip Supply Agreement will also be attached as an exhibit to the subject
Collaborative Research Agreements. Eos has also contracted to retain all or
substantially all of the intellectual property rights that may arise out of any
inventions or discoveries that may grow out of the collaborations.

CONFIDENTIAL

                                      -24-
<Page>

June 23, 2000
Re:  Collaboration Agreements
Page 2


Because of the nature of our contractual arrangements with Affymetrix, please
sign in the indicated space below to certify that Affymetrix agrees that Eos may
transfer GeneChips(R) under the circumstances set forth above. Thank you very
much for your assistance.

Sincerely,


/s/ David W. Martin, Jr.
---------------------------
David W. Martin, Jr., M.D.
President and Chief Executive Officer
Eos Biotechnology, Inc.


Dated:    June 29, 2000
      ---------------------


/s/ Susan E. Siegel
---------------------------
Susan E. Siegel, President
Affymetrix, Inc.

CONFIDENTIAL

                                      -25-
<Page>

                                    EXHIBIT E
           Expression Array Rights for Not-for-Profit Sample Providers

"Chip Improvement Inventions" shall mean all inventions conceived or reduced to
practice using Expression Probe Arrays that relate to (a) manufacturing, layout
and packaging of probe arrays; (b) assay techniques that may be used in
connection with probe array-type products (including techniques related to
nucleic acid extraction, amplification, labeling, dilution and other processes);
and (c) software analysis techniques relating to the extraction of data from
probe arrays and storing such data in a computer file or other storage media.
Chip Improvement Inventions shall not include expression data or discoveries
derived therefrom, targets identified through the use of the Expression Probe
Arrays or correlations between genetic sequences and function.

"Expression Probe Array(s)" shall mean expression probe arrays for which target
sequences have been selected by AFX and/or by Eos.

1. RESTRICTED USE RIGHTS-Not-for-Profit Sample Provider may only use the
Expression Probe Arrays provided by EOS to identify the presence and/or levels
of expressed nucleic acid sequences in the course of Not-for-Profit Sample
Provider's collaboration with EOS. In addition, except to the extent permitted
by applicable law and solely for the purpose(s) contemplated by such law,
Not-for-Profit Sample Provider agrees not to (a) transfer an Expression Probe
Array to any third party; (b) provide services to or on behalf of any third
party that relate to an Expression Probe Array; (c) distribute, transfer,
license or otherwise make available to a third party any data or database that
is obtained from the use of an Expression Probe Array; (d) use an Expression
Probe Array or data therefrom in a clinical diagnostic setting where data from
an identifiable individual's sample is given to such individual or their
caregiver; (e) reverse engineer, adapt or modify an Expression Probe Array; or
(f) use or allow anyone to use an Expression Probe Array more than once. Not-for
Profit Sample Provider agrees that this agreement benefits and is enforceable by
AFX. In the event of any ambiguity in applying this Section 1, the burden shall
be on Not-for-Profit Sample Provider to reasonably demonstrate compliance with
the terms herein.

2. INTELLECTUAL PROPERTY-Except to the extent prohibited by applicable law, in
which case Not-for-Profit Sample Provider shall grant to AFX the license to Chip
Improvement Inventions permitted by law, Not-for-Profit Sample Provider hereby
assigns to AFX all Chip Improvement Inventions and agrees to promptly report all
Chip Improvement Inventions to AFX.

CONFIDENTIAL

                                      -26-
<Page>

                                    EXHIBIT F
        Request For Credit Form for Probe Arrays and Custom Probe Arrays


Quarter begin date:
                   ---------------------

a. Array Part #
                                        ----------- ----------- -----------

b. #arrays used for Expression Research
                                        ----------- ----------- -----------

c. price paid
                                        ----------- ----------- -----------
d. Expression Research Array Price
                                        ----------- ----------- -----------

e. Net price difference
                                        ----------- ----------- -----------

f. Credit (e x b)
                                        ----------- ----------- -----------


g. Total Credit
                                                                -----------


This credit shall be applicable only toward future purchases of Probe Arrays or
Custom Probe Arrays and shall not be applied to greater than 50% of the total
array cost on any single order.


------------------------------
David Martin

------------------------------
Date

CONFIDENTIAL

                                      -27-