<PAGE>


                                  CONFIDENTIAL
                           EXCLUSIVE LICENSE AGREEMENT

          This Exclusive License Agreement (this "AGREEMENT") is entered into as
of the 23rd day of December, 1997 (the "Effective Date") by and between the Fred
Hutchinson Cancer Research Center, a Washington non-profit corporation (the
"FHCRC"), and Rosetta Inpharmatics, Inc., a Delaware corporation (the
"LICENSEE").

                                    RECITALS

          A. FHCRC is the owner by assignment from Stephen H. Friend and Leland
Hartwell (the "Inventors") of the PATENT RIGHTS as defined in this Agreement
together with certain confidential information relating thereto;

          B. FHCRC is committed to a policy that ideas or creative works
produced at FHCRC should be used for the greatest possible public benefit and
believes that every reasonable incentive should be provided for the prompt
introduction of such ideas into public use, all in a manner consistent with the
public interest;

          C. LICENSEE desires to obtain an exclusive worldwide license in order
to practice the above referenced invention covered by the PATENT RIGHTS in the
United States and in certain foreign countries, and to manufacture, use and sell
in the commercial market the products made in accordance therewith; and

          D. FHCRC is willing to grant such a license to LICENSEE subject to the
terms and conditions of this Agreement.

                              TERMS AND CONDITIONS

          The parties agree as follows:

                             ARTICLE 1- DEFINITIONS

         1.1 PATENT RIGHTS means rights of FHCRC in, to and under the issued
United States patents and patent applications listed in APPENDIX A, the
inventions described therein, as well as all continuations and divisions
thereof, all continuations-in-part to the extent one or more of their claims are
directed to the subject matter of the patent applications listed in APPENDIX A
as of the Effective Date hereof, reissues, reexaminations, extensions and
foreign counterparts thereof, which will automatically be deemed incorporated in
and added to this Agreement and shall periodically be added to APPENDIX A.


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


<PAGE>

         1.2 LICENSED PROCESSES means any process described and claimed in
PATENT RIGHTS.

         1.3 LICENSED PRODUCT means a product described and claimed in the
PATENT RIGHTS or a product that is manufactured or covered by one or more
LICENSED PROCESSES.

         1.4 AFFILIATE means any company, corporation, or business in which
LICENSEE owns or controls at least a fifty percent (50%) ownership interest (or
such lesser percentage which is the maximum allowed to be owned by a foreign
corporation in a particular jurisdiction) or which directly or indirectly owns
or controls more than a fifty percent (50%) ownership interest in LICENSEE.

         1.5 TECHNICAL INFORMATION means inventions (whether or not patentable),
processes, materials, formulas and know-how directly related to the subject
matter of the PATENT RIGHTS that are developed by the Inventors and owned or
controlled by FHCRC as of the date of this Agreement or hereafter. All TECHNICAL
INFORMATION shall be communicated to LICENSEE in writing.

         1.6 TECHNOLOGY means any and all (a) PATENT RIGHTS and (b) TECHNICAL
INFORMATION supplied by FHCRC to LICENSEE.

         1.7 IMPROVEMENT means any invention, discovery or know-how (whether
or not patentable) which (a) is an improvement or modification of the
TECHNOLOGY or otherwise directly relates to the subject matter of the PATENT
RIGHTS; (b) is not licensed as of the Effective Date; (c) is made within
five (5) years from the Effective Date hereof; (d) is conceived or reduced to
practice by one or more of the Inventors; and (e) is owned by FHCRC or LICENSEE
with the right to license it.

                                ARTICLE 2- GRANT

         2.1 EXCLUSIVE LICENSE. FHCRC hereby grants to LICENSEE and LICENSEE
accepts, subject to the terms and conditions hereof, the exclusive worldwide
license, under the PATENT RIGHTS, to make, have made, use, sell, import, offer
for sale and have sold the LICENSED PRODUCTS, to practice the TECHNOLOGY and to
practice the LICENSED PROCESSES, for all uses in all fields, for the Term
permitted in Section 3.1 of this Agreement (the "License"). The License includes
the right to grant sublicenses, subject to the provisions of Section 2.2(f)
below.

         2.2 RESTRICTIONS ON LICENSE. Notwithstanding any other provision of
this Agreement, the License is subject to the following policies, obligations
and/or conditions:

                  (a) FHCRC's Patents and Inventions Policy adopted September
30, 1983,


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -2-

<PAGE>

Public Laws 96-517 and 98-620 and FHCRC's obligations under agreement
with other sponsors of research. Any right granted in this Agreement greater
than that permitted under Public Laws 96-517 or 9 8-620 shall be subject to
modification as may be required to conform to the provisions of the statutes.

                  (b) LICENSEE agrees during the period of exclusivity of the
License that any LICENSED PRODUCT produced for sale in the United States will be
manufactured substantially in the United States.

                  (c) For research purposes only and not for any commercial
purpose, FHCRC has the right to make and to use, but not to sublicense the
TECHNOLOGY without LICENSEE'S written consent (which consent will not be
unreasonably withheld if the sublicense is to an academic or research
institution, is for research purposes only and such institution agrees to be
bound by the restrictions of this Section 2.2(c)). FHCRC agrees that it will not
use the TECHNOLOGY in research subject to licensing or consulting obligations to
a third party (except for the federal government), without the written consent
of LICENSEE.

                  (d) LICENSEE shall use reasonable effort to introduce the
LICENSED PRODUCTS into the commercial market as soon as practicable, consistent
with sound and reasonable business practices and judgment, and thereafter
endeavor to keep LICENSED PRODUCTS reasonably available to the public.

                  (e) FHCRC shall have the right to render this Agreement
non-exclusive at any time after five (5) years of the Effective Date upon
sixty (60) days prior written notice to LICENSEE if, in FHCRC's reasonable
judgment, LICENSEE has not put a LICENSED PRODUCT into commercial use
directly or through a sublicense and is not keeping the LICENSED PRODUCT
reasonably available to the public, or is not demonstrably engaged in
research, development, manufacturing, marketing or licensing, as appropriate,
directed toward these ends. In making this determination FHCRC shall take
into account the normal course of such programs conducted with sound and
reasonable business practices and judgment, then-prevailing market
conditions, the existence of new or more competitive technologies, and shall
take into account the reports provided hereunder by LICENSEE. FHCRC's
determination to render this Agreement non-exclusive will become effective at
the end of the sixty (60) day notice period unless LICENSEE shall have
demonstrated fulfillment of its obligation under this Section 2.2(e).

                  (f) LICENSEE may grant sublicenses for any rights granted
under the License. All sublicenses granted by LICENSEE hereunder shall include a
requirement that the sublicensee use reasonable efforts to bring the subject
matter of the sublicense into commercial use consistent with Section 2.2(e) and
shall expressly bind the sublicensee to meet LICENSEE's obligations to FHCRC
under this Agreement relating to sublicenses, including, but not limited to,
obligations under Section 2.2(e). Copies of all executed sublicense agreements
pertaining to any rights granted under the License shall promptly be provided to
FHCRC. FHCRC agrees to maintain each such sublicense agreement and all
information relating thereto in confidence.


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -3-

<PAGE>

          2.3 IMPROVEMENTS. FHCRC and LICENSEE agree to promptly disclose to
each other all IMPROVEMENTS to the TECHNOLOGY in a writing, in sufficient
detail for LICENSEE and FHCRC to evaluate each such IMPROVEMENT. FHCRC grants
to LICENSEE the option to an exclusive license in each such IMPROVEMENT owned
by FHCRC for a period of six (6) months from the date of disclosure to
LICENSEE. LICENSEE shall have the right to exercise the option to an
exclusive license to such IMPROVEMENT at any time during the six (6) months
option period by notifying FHCRC in writing. Upon exercise of the option in
writing, the IMPROVEMENT will be included in the TECHNOLOGY and licensed in
the License without additional charge to LICENSEE. If the option is not
exercised by LICENSEE, FHCRC shall be free to license such IMPROVEMENT to a
third party or parties without any obligation to LICENSEE. LICENSEE hereby
grants to FHCRC a nonexclusive, irrevocable, royalty-free license for
research purposes to its interests in any IMPROVEMENT; provided that such
IMPROVEMENT will be deemed to be TECHNOLOGY under this Agreement and subject
to the restrictions set forth in Section 2.2(c). Notwithstanding the
foregoing, to the extent FHCRC develops any improvement to the TECHNOLOGY
based on Proprietary Information owned by LICENSEE that would be an
IMPROVEMENT but for the fact that it was conceived or reduced to practice by
someone other than one or more of the Inventors, FHRCR shall first offer such
improvement to LICENSEE. For a period of ninety (90) calendar days following
notice to LICENSEE by FHCRC of such improvement, FHCRC and LICENSEE shall in
good faith endeavor to negotiate an agreement with respect to LICENSEE's
rights to such improvement. In the event FHCRC and LICENSEE fail to enter
into such agreement within such ninety (90) day period, FHCRC shall, for a
period of one year thereafter, have the right to enter into an agreement
regarding such improvement with a third party provided that the terms and
conditions offered to such third party shall not be more favorable than the
terms and conditions last specified by FHCRC to LICENSEE in a written
proposal unless first offered to LICENSEE. Thereafter, FHCRC shall be free to
enter into an agreement regarding such improvement with a third party without
further restriction under this Section 2.3.

                          ARTICLE 3- TERM OF AGREEMENT

          The term of this Agreement commences on the Effective Date and,
subject to earlier termination as provided in Article 2.2(e), ends on the later
of(a) the expiration date of the last to expire of the PATENT RIGHTS and (b)
twenty (20) years from the Effective Date (the "Term") unless otherwise provided
in this Agreement.

                         ARTICLE 4- EQUITY AND PAYMENTS

          4.1 EQUITY. As partial consideration for the License, LICENSEE agrees
to issue to FHCRC shares of LICENSEE's Common Stock equal to four percent (4%)
of fully-diluted capital stock of LICENSEE immediately following the closing of
LICENSEE's Series A Preferred Stock financing. The Common Stock issued to FHCRC
shall be subject to the terms and conditions set forth in the Stock Purchase
Agreement attached hereto as APPENDIX B.


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -4-

<PAGE>

          4.2 PAYMENTS. On June 30 of each year, commencing on June 30
following the date on which the first patent covered under the Patent Rights
is issued in the United States (the "United States Patent Issue Date") and
continuing thereafter until the earlier of (a) termination of this Agreement
or (b) the date on which the Company grants a sublicense to the Technology to
a non-Affiliate in a transaction where the aggregate value of the license
fees, research funding and similar compensation to LICENSEE is greater than
[***], LICENSEE shall make an annual payment of $50,000 (the "ANNUAL PAYMENT").

                              ARTICLE 5 - REPORTING

          5.1 RESEARCH AND DEVELOPMENT PLAN. Within sixty (60) days following
execution of this Agreement, LICENSEE shall provide to FHCRC a written research
and development plan and business plan for introducing LICENSED PRODUCTS into
commercial use.

          5.2 ANNUAL REPORTS. LICENSEE shall provide written reports within
sixty (60) days after December 31 of each calendar year which shall include the
following information: reports of progress on research and development,
regulatory approvals, manufacturing, sublicensing, marketing and sales during
the preceding twelve (12) months as well as plans for the coming year. If
LICENSEE's progress differs from that anticipated in the plan provided to FHCRC
under Section 5.1, LICENSEE shall explain the reasons for the difference and
propose modified plans for FHCRC's review and comments, which comments shall be
given serious consideration by LICENSEE. LICENSEE shall also provide any
reasonable additional data FHCRC requires to evaluate LICENSEE's performance.

          5.3 FINANCIAL REPORTS. LICENSEE shall provide to FHCRC quarterly
fmancial statements for the immediately preceding quarter within thirty (30)
days after the end of each quarter.

          5.4. CONFIDENTIALITY OF REPORTS. All such reports shall be maintained
in confidence by FHCRC, except as required by law, including Public Laws 96-517
and 98-620.

                    ARTICLE 6- DOMESTIC AND FOREIGN PATENT FILING
                                             AND MAINTENANCE

          6.1 RESPONSIBILITY. Throughout the term of this Agreement, LICENSEE,
at its own expense, shall have the right, but shall not be obligated, to
prepare, file, prosecute and defend against third party oppositions any and all
United States and foreign patent applications, and to maintain any and all
United States and foreign patents included within the PATENT RIGHTS; PROVIDED,
HOWEVER, that LICENSEE shall first consult with FHCRC as to the preparation,
filing, prosecution and defense of such applications and maintenance of such
patents and shall promptly furnish to FHCRC copies of all documents relevant to
such preparation, filing, prosecution, defense, or maintenance and shall keep
FHCRC fully advised of the same. FHCRC shall have the right to review and make
recommendations with respect to all such patent applications and patents and
proceedings relating thereto. In the event of a dispute between LICENSEE and


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -5-

<PAGE>

FHCRC as to such preparation, filing, prosecution, defense, or maintenance,
FHCRC's decision shall be controlling on such subject. In the event that
LICENSEE elects not to file, prosecute, or defend such applications or maintain
such patents, LICENSEE shall so notify FHCRC in writing not less than sixty (60)
days prior to such action, in which event FHCRC shall have the right to conduct
such filing, prosecution, defense, or maintenance. Notwithstanding any of the
foregoing, FHCRC shall have the right, on any reasonable basis, and upon written
notice to LICENSEE, to take over and assume responsibility for the preparation,
filing, prosecution and defense of any and all United States and foreign patent
applications included within PATENT RIGHTS and maintenance of any and all United
States and foreign patents included within PATENT RIGHTS. In the event that
FHCRC conducts such filing, prosecution, defense, or maintenance as provided
herein, FHCRC shall first consult with LICENSEE as to such preparation, filing,
prosecution, defense, or maintenance and shall keep LICENSEE fully advised of
the same; in such case, LICENSEE shall have the right to review and make
recommendations with respect to all such patent applications and patents and
proceedings relating thereto.

          6.2 REIMBURSEMENT. LICENSEE shall reimburse FHCRC for all reasonable
and documented expenses FHCRC has incurred for the preparation, filing,
prosecution and maintenance of PATENT RIGHTS, including any interference
proceedings, and shall reimburse FHCRC for all such expenses incurred in
connection with the PATENT RIGHTS.

          6.3 NOTICE. Each party shall provide to the other prompt notice as to
all matters which come to its attention and which may affect the preparation,
filing, prosecution, defense or maintenance of any such patent applications or
patents. FHCRC and LICENSEE shall cooperate fully and in good faith in the
preparation, filing, prosecution, defense and maintenance of PATENT RIGHTS and
of all patents and patent applications licensed to LICENSEE hereunder, including
the execution of all papers and instruments so as to enable FHCRC to apply for,
to prosecute and to maintain patent applications and patents in FHCRC's name in
any country.

          6.4 NON-PAYMENT. If LICENSEE elects not to pay the expenses of a
patent application or patent included within PATENT RIGHTS, LICENSEE shall
notify FHCRC not less than sixty (60) days prior to such action and shall
thereby surrender its rights under Section 2.1 of this Agreement with respect to
such patent or patent application.

                             ARTICLE 7- ENFORCEMENT

          7.1 NOTICE OF INFRINGEMENT. Each party agrees to notify the other
promptly of any infringement of the PATENT RIGHTS of which such party becomes
aware.

          7.2 ACTION BY LICENSEE. During the Term, subject to FHCRC prior
written consent (not to be unreasonably withheld), LICENSEE has the right to
prosecute any infringements of the PATENT RIGHTS, at its sole expense, and FHCRC
hereby agrees that LICENSEE may include FHCRC as a party plaintiff in any such
suit, without expense of FHCRC. The total cost


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -6-

<PAGE>

of any such action commenced or defended solely by LICENSEE shall be borne by
LICENSEE and LICENSEE shall keep any recovery or damages for infringement
derived from the action. Before LICENSEE commences any such infringement action,
LICENSEE shall give careful consideration to the views of FHCRC and to potential
effects on the public interest in making its decision whether or not to commence
such an action. FHCRC agrees to cooperate reasonably in any such action
initiated by LICENSEE including supplying essential documentary evidence and
making essential witnesses then in FHCRC's employment available at LICENSEE's
expense.

          7.3 ACTION BY FHCRC. If LICENSEE fails to initiate an infringement
action within ninety (90) days after notification or knowledge of the basis for
such action and LICENSEE is not already a party in an infringement action
including any patent included within PATENT RIGHTS, or if FHCRC reasonably
withholds its consent pursuant to Section 7.2, FHCRC shall have the right, and
in the case of reasonably withholding its consent pursuant to Section 7.2 shall
be obligated, to prosecute at its own expense all infringements of the PATENT
RIGHTS, and LICENSEE hereby agrees that FHCRC may include LICENSEE as a party
plaintiff in any such suit, without expense to LICENSEE. The total cost of any
such action commenced or defended solely by FHCRC shall be borne by FHCRC and
FHCRC shall keep any recovery or damages for past infringement derived from the
action.

                    ARTICLE 8- INDEMNIFICATION AND INSURANCE

         8.1 INDEMNIFICATION. LICENSEE assumes responsibility for and shall
defend, indemnify and hold FHCRC, its directors, officers, managers, agents,
students, doctors and employees (the "Indemnified Parties") harmless from any
and all liability, losses, expenses, damages, assessments and claims arising out
of or resulting from (a) the use, sale or any disposition of LICENSED PRODUCTS
by LICENSEE or its AFFILIATES, (b) the practice of the LICENSED PROCESSES by
LICENSEE or its AFFILIATES, or (c) the use, sale or other disposition of the
LICENSED PRODUCT or LICENSED PROCESSES by others who receive LICENSED PRODUCTS
or LICENSED PROCESSES directly or indirectly from LICENSEE, its AFFILIATES,
agents or representatives. Notwithstanding the foregoing, LICENSEE shall have no
obligation to indemnify and hold harmless the Indemnified Parties (i) if the
claim is found to be based upon the gross negligence or willful misconduct of
any of the Indemnified Parties, or (ii) if the Indemnified Parties fail to give
LICENSEE prompt notice of any claim it receives and such failure materially
prejudices LICENSEE, or (iii) solely to the extent of indemnification for legal
fees and disbursements of counsel of the Indemnified Parties, unless LICENSEE is
given the opportunity to control the defense of such action, or (iv) unless
LICENSEE is given the opportunity to approve any settlement; and provided
further that, except in the event of a material conflict of interest, LICENSEE
will not be liable for attorney's fees of the Indemnified Parties after assuming
control of the defense or settlement.

         8.2 INSURANCE. Upon the earlier of any: (a) testing or use in human
subjects or (b) sale of a LICENSED PRODUCT, LICENSEE will have FHCRC named as an
additional insured on LICENSEE's product liability insurance policies, with
limits consistent with sound business practice. Such policies shall not be
terminated without thirty (30) days prior written notice to


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -7-

<PAGE>

FHCRC. LICENSEE shall provide FHCRC with written evidence of the insurance
and a copy of the policy upon request.

         8.3 LEGAL ACTION. In the event any legal action is commenced against
LICENSEE involving the TECHNOLOGY, whether or not FHCRC is named as a ~5arty to
the legal action, LICENSEE shall keep FHCRC or its attorney nominee fully
advised of the progress of the legal action and shall reimburse FHCRC for its
reasonable legal costs (including attorney's fees) incurred as a result of
FHCRC's monitoring of such action, FHCRC's being named a party to any such legal
action, or when FHCRC's employees or agents are called as witnesses therein or
asked to testify for or consult with LICENSEE in connection therewith. FHCRC
agrees to cooperate with LICENSEE, to the extent reasonably possible, in any
legal action brought pursuant to this Section 8.3.

                             ARTICLE 9- ARBITRATION

          Any dispute, other than a question relating to patent validity or
infringement, between the parties hereunder which cannot be resolved by good
faith negotiation between the parties over a period of at least sixty (60) days
shall be resolved by arbitration before a panel of three arbitrators under the
then current rules and procedures of the American Arbitration Association (the
"AAA"), or other rules and procedures as the parties may agree. Each party shall
bear its own costs incurred in connection with such arbitration and the fees,
expenses and costs of the AAA, the arbitrator(s) and the arbitration proceeding
not incurred solely by one party shall be divided equally between the parties.
The arbitral award shall be binding and conclusive on both parties and may be
enforced in any court of competent jurisdiction.

                      ARTICLE 10- TERMINATION OF AGREEMENT

          10.1 TERMINATION ON PAYMENT DEFAULT. At FHCRC's option, FHCRC may
terminate this Agreement effective thirty (30) days after giving written notice
in the event LICENSEE fails to pay any Annual Payment or other amounts owed
under this Agreement when due, unless the payment default is cured or shown to
be non-existent within such thirty (30) day period, in which case the Agreement
will remain in effect.

          10.2 TERMINATION ON OTHER DEFAULTS. This Agreement may be
terminated by either party upon a material breach by the other party other
than a payment default which is governed by Section 10.1, effective
ninety (90) days after giving written notice to the breaching party of such
termination under this Section 10.2 and specifying such breach, unless the
default is cured or shown to be non-existent within the ninety (90) days
period, in which case the Agreement will remain in effect.

          10.3 TERMINATION ON BANKRUPTCY OR INSOLVENCY. Subject to any
provisions of the federal bankruptcy laws limiting rights of termination, this
Agreement will automatically terminate if LICENSEE files for protection under
federal bankruptcy laws, becomes insolvent,


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -8-

<PAGE>

makes an assignment for the benefit of creditors, appoints or suffers
appointment of a receiver or trustee over its property, files a petition under
any bankruptcy or insolvency act or has any such petition filed against it or
files for dissolution.

          10.4 TERMINATION BY LICENSEE. LICENSEE shall have the right to
terminate this Agreement at any time upon thirty (30) days prior written notice
to FHCRC.

          10.5 EFFECT OF TERMINATION ON SUBLICENSES. Any sublicenses granted by
LICENSEE under this Agreement shall provide for termination or assignment to
FHCRC, at the option of FHCRC, of LICENSEE's interest therein upon termination
of this Agreement.

          10.6 SALE OF PRODUCTS ON TERMINATION. In the event that FHCRC
terminates this Agreement as permitted herein, LICENSEE shall have the right
for three (3) months to sell all LICENSED PRODUCTS on hand at the time of
receipt of notice of termination if any and all payments due FHCRC are paid
when due in accordance with this Agreement.

          10.7 EFFECT OF TERMINATION. Upon termination of the Agreement for any
reason, and subject to LICENSEE's rights under Section 10.6, each party shall
return to the other party all TECHNOLOGY owned by such other party and
thereafter continue to maintain the confidentiality thereof, and refrain from
use thereof or the disclosure thereof to any third party as required by Article
13, and all other rights in TECHNOLOGY and LICENSED PRODUCTS granted under
Article 2 shall expire and revert to the owner thereof. Upon termination of this
Agreement, each party will turn over to the other party all Proprietary
Information owned by such other party and all documents or data storage media
containing any such Proprietary Information owned by such other party and any
and all copies thereof, and each party will delete all Proprietary Information
owned by such other party from its documents or data storage media. Should
either party terminate this Agreement as permitted herein, the other party shall
not be able to claim from the terminating party, any damages or compensation for
losses or expenses incurred solely as a result of the termination. FHCRC shall
be entitled to retain all equity issued and payments made under this Agreement,
notwithstanding termination of this Agreement for any reason.

          10.8 SURVIVAL OF RIGHTS AND DUTIES. Rights and duties hereunder which
by their terms or nature survive the termination or expiration of this Agreement
shall so survive such termination or expiration, including without limitation
duties under Sections 5.3, 7, 8, 9, 10.6, 10.7, 12, 13, 16.1, 16.7, 16.8, 16.9
and 16.10.

                    ARTICLE 11- REPRESENTATIONS AND COVENANTS

          11.1 FHCRC REPRESENTATIONS AND WARRANTIES. FHCRC represents and
warrants that all right, title, and interest in the patent applications or
patents comprising the PATENT RIGHTS listed in APPENDIX A have been or will be
assigned to it and are owned by it (subject to Government Rights under 35 U.S.C.
Section 200 et seq.), that FHCRC has the authority to issue licenses under the
PATENT RIGHTS, that all corporate action of FHCRC required to authorize


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -9-

<PAGE>

and perform this Agreement and the transactions contemplated hereby has been
taken; that this Agreement has been duly executed and delivered by FHCRC and is
a legal, valid and binding obligation of FHCRC and that FHCRC is duly organized
and validly existing under the laws of the State of Washington.

          11.2 FHCRC DISCLAIMERS. FHCRC disclaims all implied or express
warranties of any nature whatsoever concerning the validity or scope of the
PATENT RIGHTS licensed hereunder. FHCRC does not warrant that such PATENT RIGHTS
may be exploited by LICENSEE, an AFFILIATE, or sublicensee without infringing
other patents. FHCRC EXPRESSLY DISCLAIMS ANY AND ALL EXPRESS WARRANTIES, EXCEPT
THOSE STATED IN THIS ARTICLE 11, AND FURTHER DISCLAIMS ANY AND ALL IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS OF THE TECHNOLOGY, LICENSED PROCESSES
OR LICENSED PRODUCTS FOR ANY PARTICULAR USE OR PURPOSE.

          11.3 LICENSEE REPRESENTATIONS AND WARRANTIES. LICENSEE represents and
warrants to FHCRC that all corporate action of LICENSEE required to authorize
and perform this Agreement and the transactions contemplated hereby has been
taken; that this Agreement has been duly executed and delivered by LICENSEE and
is a legal, valid and binding obligation of LICENSEE; that the execution,
delivery and performance of this Agreement will not, with OR without the giving
of notice or the lapse of time or both violate any judgment, order, writ, or
decree of any court applicable to LICENSEE or result in the breach of or
conflict with or constitute a default under any corporate charter, bylaw,
commitment, contract or other agreement or instrument to which LICENSEE is a
party; that LICENSEE is duly organized and validly existing under the laws of
the State of Delaware and that it has obtained and will at all times during the
Term hold and comply with all licenses, permits and authorizations necessary to
LICENSEE's complete and timely performance of its obligations under this
Agreement which are required under any applicable statutes, laws, ordinances,
rules and regulations of the United States as well as those of all applicable
foreign governmental bodies, agencies and subdivisions, having, asserting or
claiming jurisdiction over LICENSEE or LICENSEE's performance of the terms of
this Agreement. In particular, LICENSEE:

                  (a) will be responsible for obtaining all necessary United
States Food and Drug Administration approvals and all approvals required by
similar governmental bodies or agencies of all applicable foreign countries; and

                  (b) understands and acknowledges that the transfer of certain
commodities and technical data is subject to United States laws and regulations
controlling the export of such commodities and technical data, including all
Export Administration Regulations of the United States Department of Commerce.
These laws and regulations, among other things, prohibit or require a license
for the export of certain types of technical data to certain specified
countries. LICENSEE hereby agrees and gives written assurance that it will
comply with all United States laws and regulations controlling the export of
commodities and technical data, that it will be solely responsible for any
violation of such by LICENSEE or its AFFILIATES or sublicensees,


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -10-

<PAGE>

and that it will defend and hold FHCRC harmless in the event of any legal action
of any nature occasioned by such violation.

                               ARTICLE 12- NOTICES

          All communications, including payments, notices, demands or requests
required OR permitted to be given hereunder, shall be given in writing and shall
be: (a) personally delivered; (b) sent by facsimile or other electronic means of
transmitting written documents; or (c) sent to the parties at their respective
addresses indicated herein by registered or certified U.S. mail, return receipt
requested and postage prepaid, or by private overnight mail courier service. The
respective addresses to be used for all such payments, notices, demands or
requests are as follows:

       If to FHCRC:      Fred Hutchinson Cancer Research Center
                         1100 Fairview Avenue North, C2M-027
                         Seattle, Washington 98109
                         Attention:  Catherine J. Hennings, Director,
                         Technology Transfer
                         Facsimile:   (206) 667-4732

       With copies to:   Douglas J. Shaeffer, Esq.
                         Fred Hutchinson Cancer Research Center
                         1100 Fairview Avenue North, LM-254
                         Seattle, Washington 98109
                         Facsimile: (206) 667-6590

       If to LICENSEE:   Rosetta Inpharmatics, Inc.
                         12040 - 115th Avenue N.E., Suite 210
                         Kirkland, WA 98034
                         Attention: President
                         Facsimile: (425) 821-5354

       With copies to:   Venture Law Group
                         4750 Carillon Point
                         Kirkland, WA 98033
                         Attention:   William W. Ericson
                         File No. 15822.012
                         Facsimile:  (425) 739-8750

If personally delivered, such communication shall be deemed delivered upon
actual receipt. If electronically transmitted pursuant to this Article 12, such
communication shall be deemed delivered when transmitted. If sent by overnight
courier pursuant to this Article 12, such communication shall be deemed
delivered within twenty-four (24) hours of deposit with such courier. If sent by
U.S. mail pursuant to this Article 12, such communications shall be deemed
delivered as of the date of delivery indicated on the receipt issued by the
relevant postal service,


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -11-

<PAGE>

or, if the addressee fails or refuses to accept delivery, as of the date of such
failure or refusal. Any party to this Agreement may change their address for the
purposes of this Agreement by giving notice in accordance with this Article.

                 ARTICLE 13- CONFIDENTIALITY AND NON-DISCLOSURE

         13.1 PROPRIETARY INFORMATION. Any and all information in any form
relating to the TECHNOLOGY furnished to either party (or its agents or
employees) by the other party (or its laboratories or agents or employees),
including but not limited to information regarding or relating to devices,
biological materials, methods, processes, data, drawings, documentation, patent
applications, know how and product development plans, is confidential,
proprietary, information and any and all such information is hereinafter
referred to as "Proprietary Information."

         13.2 EXCEPTIONS TO PROPRIETARY INFORMATION. As used herein,
"Proprietary Information" does not include information:.

                  (a) that at the time of disclosure to the receiving party is
  or later becomes generally available to the public through no fault of the
  receiving party;

                  (b) that is demonstrated to have been in the receiving party's
  possession prior to the time of disclosure by the disclosing party;

                  (c) that is demonstrated by a preponderance of the evidence to
  have been independently developed by the receiving party's personnel without
  reference to Proprietary Information of the disclosing party; and

                  (d) received from a third party, unless such information is
  obtained subject to a confidential disclosure agreement.

          13.3 USE OF PROPRIETARY INFORMATION. Each party agrees: (a) to hold in
strict confidence and trust and maintain as confidential all Proprietary
Information disclosed by the other party; (b) not to disclose any such
Proprietary Information or any information derived therefrom to any person,
except to those employees or legal counsel of the receiving party who are
required to receive the Proprietary Information for the purposes described in
this Agreement and who are bound by the provisions of this Agreement; and (c) to
use the Proprietary Information only for the purposes described in this
Agreement.

          13.4 OWNERSHIP OF PROPRIETARY INFORMATION. Each party agrees that all
Proprietary Information disclosed by the other party will at all times be and
remain the sole property of the disclosing party and the disclosing party is the
sole owner of all patents, copyrights and other intellectual property rights and
other proprietary rights related to the Proprietary Information disclosed by it
and conceived or made by the disclosing party's employees.


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -12-

<PAGE>>

          13.5 TERM OF CONFIDENTIALITY. The obligations of confidentiality
provided herein shall continue in force and effect for [***] from the date of
termination of this Agreement, whether by lapse of the Term hereof or
otherwise, unless extended or limited by mutual agreement executed in writing
by an officer of each party; PROVIDED, HOWEVER, that if this Agreement is
terminated before the end of the Term due to a default by LICENSEE, the
obligation of confidentiality shall continue for [***] from the end of the
Term assuming no early termination.

                           ARTICLE 14- PATENT MARKING

          Subsequent to the issuance of any patent included in the PATENT RIGHTS
and provided FHCRC advises LICENSEE of the patent number or numbers of any such
issued patents, LICENSEE agrees to mark and to have marked by its sublicensees
every LICENSED PRODUCT manufactured, used or sold in the United States by
LICENSEE, its AFFILIATES or its sublicensees in accordance with the statutes of
the United States relating to the marking of patented articles. All LICENSED
PRODUCTS shipped to or sold in other countries shall be marked in such a manner
as to conform with the patent laws and practice of the countries of manufacture
or sale.

                          ARTICLE 15- RIGHT TO PUBLISH

          Nothing in this Agreement shall be construed as prohibiting either
party from presenting or publishing any of the results of their own research
on the TECHNOLOGY, including without limitation research results which
constitute Proprietary Information; PROVIDED, HOWEVER, that each party agrees
to provide the other party with a copy of any such presentation or
publication at least thirty (30) days prior to submission or presentation and
further agrees to delay publication for a period not to exceed sixty (60) days,
which is sufficient to allow the other party to take steps necessary to protect
any intellectual property, including the filing of any patent applications
and/or deletion of its confidential information.

                            ARTICLE 16- MISCELLANEOUS

          16.1 APPLICABLE LAW. The rights and obligations of the parties under
this Agreement shall be governed by and construed in accordance with the laws of
the State of Washington.

          16.2    NO MODIFICATION. This Agreement may not be amended except by
an instrument in writing signed by both parties.

          16.3 ASSIGNMENT. The Agreement shall be binding on the parties hereto
and upon their respective heirs, administrators, successors and assigns. This
Agreement may not be assigned by LICENSEE or by operation of law without the
prior written consent of FHCRC, which consent shall not be unreasonably
withheld; provided, that LICENSEE may assign this Agreement without FHCRC's
consent to any entity that acquires all or substantially all of its assets or
business relating to LICENSED PRODUCTS and LICENSED PROCESSES, by merger or


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -13-

<PAGE>

otherwise.

          16.4 NON-PROFIT STATUS. LICENSEE acknowledges that FFICRC is a
non-profit organization qualifying for and holding the status of an exempt
organization under Section 50l(c)(3) of the United States Internal Revenue Code
("SECTION 501(c)(3) STATUS"). If the Internal Revenue Service (the "IRS")
determines, or a determination by FHCRC based on advice of legal or tax counsel
is reasonably made, that any part or all of this Agreement will jeopardize
FHCRC's Section 501(c)(3) Status, the parties agree to meet and confer in good
faith to amend this Agreement to the extent necessary to satisfy IRS
requirements for retention of FHCRC's Section 501(c)(3) Status. If FHCRC and
LICENSEE cannot agree within thirty (30) days after commencing negotiations
regarding the amendments to be made to this Agreement in order for FHCRC to
retain its Section 501(c)(3) Status, FHCRC may terminate this Agreement
effective upon giving written notice to LICENSEE of termination under this
Section 16.4.

          16.5 CONFLICTS WITH GRANTS. LICENSEE understands and acknowledges that
agreements between FHCRC and agencies of the United States government funding
FHCRC's programs may contain clauses granting patent and/or other rights to the
agencies or the U.S. government. LICENSEE agrees that the rights granted to it
under this Agreement shall be subject to any rights of the agencies and the U.S.
government. If a conflict arises, the provisions of any U.S. government agency
funding agreement and/or regulation shall prevail over any conflicting
provisions of this Agreement and FHCRC will have no liability to LICENSEE as a
result of such conflict.

          16.6 BOARD OBSERVER. During the Term, FHCRC shall be entitled to have
one representative of FHCRC attend meetings of the Board of Directors of
LICENSEE, which representation shall be Leland Hartwell or such other
representative as FHCRC and LICENSEE shall mutually agree upon. LICENSEE agrees
to give FHCRC timely notice of Board of Directors meetings of LICENSEE.
Notwithstanding the foregoing, LICENSEE may exclude the FHCRC representative
from certain meetings or portions of certain meetings if LICENSEE reasonably
determines that attendance of the FHCRC representative would jeopardize
attorney-client privilege or proprietary rights of LICENSEE, violate
confidentiality requirements of a third party or otherwise be illegal or
improper.

          16.7 USE OF NAME. No party shall use the name of the other party or
reveal the terms of this Agreement in any publicity or advertising without the
prior written approval of the other party, except that (a) any party may use the
text of a written statement approved in advance by the other party without
further approval; (b) any party shall have the right to identify the other party
and to disclose the terms of this Agreement as required by applicable securities
laws or other applicable law or regulation; and (c) any party may disclose that
a licensing relationship exists between the parties and may disclose the name of
the other party in that context.

          16.8 NOTICES. All letters, documents, or other materials of a written
or physical nature, required by or relating to this Agreement shall be in
English and sent to the party at the address given in Article 12.


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -14-

<PAGE>

          16.9 INDEPENDENT PARTIES. The parties to this Agreement are
independent contractors and not agent of the other. This Agreement shall not
constitute a partnership or joint venture, and neither party may be bound by the
other to any contract, arrangement or understanding except as specifically
stated herein.

         16.10 SEVERABILITY. Should a court of competent jurisdiction later
  consider any provision of this Agreement to be invalid, illegal, or
  unenforceable, it shall be considered severed from this Agreement. All other
  provisions, rights and obligations shall continue without regard to the
  severed provision, provided that the remaining provisioni of this Agreement
  are in accord with the intention of the parties.

         16.11 PROCEEDINGS. In the event any party to this Agreement commences
  any action or proceeding, including an appeal of an action or proceeding,
  against the other, or otherwise retains an attorney, by reason of any breach
  or claimed breach of any provision of this Agreement, or to seek a judicial
  declaration of rights hereunder or judicial or equitable relief, the
  prevailing party in such action or proceeding shall be entitled to recover its
  reasonable attorneys' fees and costs. Venue of any such legal or equitable
  action shall lie in Seattle, Washington. Each of LICENSEE and FHCRC hereby
  submits to the jurisdiction of the Federal District Court of Western
  Washington located in Seattle, Washington, and hereby agrees to accept service
  of process by certified mail, return receipt requested, effective upon
  delivery to LICENSEE or FHCRC, as the case may be.

         16.12 COUNTERPARTS. This Agreement may be executed simultaneously 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.


                            [Signature page follows:


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


                                      -15-

<PAGE>


FRED HUTCHINSON CANCER RESEARCH CENTER         ROSETTA INPHARMATICS, INC.


By: /s/                                        By: /s/ John J. King, II
   -----------------------------------             ---------------------------

Printed                                        Printed
Name:                                          Name: John J. King, II
     ---------------------------------               -------------------------

Title:                                         Title: Sr. Vice President & Co.
      --------------------------------                ------------------------

Date:                                          Date: 1/12/97
     ---------------------------------               -------------------------





                 SIGNATURE PAGE TO EXCLUSIVE LICENSE AGREEMENT


*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.


<PAGE>

                                   Appendix A
                                   ----------

                         PATENT APPLICATIONS AND PATENTS

<TABLE>
<CAPTION>

                        Patent                                              File or
Patent NO.          Applicant No.                          Country        Issue Date    Title/Inventor
----------          -------------                          -------        ----------    --------------
<S>                 <C>                                    <C>            <C>           <C>

                    [***]                                   [***]            [***]      [***]

                    [***]                                   [***]            [***]      [***]

</TABLE>




*  Material has been omitted pursuant to a request for confidential treatment,
   and such material has been filed separately with the SEC.