<PAGE>

                                                                   Exhibit 10.66

     Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.

                                                            Nonexclusive License
                                                                      97-107-.MW
                                                                        11/20/97

                                LICENSE AGREEMENT

Effective as of November 20, 1997 ("Effective Date"), THE BOARD OF TRUSTEES OF
THE LELAND STANFORD JUNIOR UNIVERSITY, a body having corporate powers under the
laws of the State of California ("STANFORD"), and Ontogeny, Inc., having a
business address at 45 Moulton Street, Cambridge, MA 02138-1118 ("LICENSEE"),
agree as follows;

1.    BACKGROUND

1.1   STANFORD has certain rights to biological material known as "Transgenic
      Mice Carrying a Reporter Gene for the Hedgehog Signaling Pathway"
      ("Biological Material") developed in the laboratory of Dr. Matthew Scott,
      a Howard Hughes Medical Institute ("HHMI") investigator at STANFORD, and
      described in Stanford docket S97-107.

1.2   STANFORD desires to have the Biological Material utilized at the earliest
      possible time in order that products resulting therefrom may be available
      for public use and benefit.

1.3   LICENSEE wishes to acquire a license to said Biological Material to use
      Biological Material in the Licensed Field of Use.

1.4   Biological Material was developed in the course of research supported by
      the Howard Hughes Medical Institute.

2.    DEFINITIONS

2.1   "Biological Material" means "Transgenic Mice containing an E. Coli
      laczgene inserted in the patched gene" and provided to LICENSEE pursuant
      to this Agreement.

2.2   "Licensed Field of Use" means any use of the Biological Material for
      research purposes. The Biological Material may be used to identify,
      discover or characterize products. The Licensed Field of Use specifically
      excludes any use of Biological Material which requires U. S. F. D. A.
      approval, including any human in vitro and human in vivo diagnostic or
      therapeutic applications, and any human in vivo use for whatever purpose.

3.    GRANT

3.1   STANFORD hereby grants, and LICENSEE accepts, a nonexclusive license to
      the Biological Material in the Licensed Field of Use. Said license does
      not include the right to grant sublicense(s). However, if LICENSEE is
      collaborating with a corporate partner, such corporate partner shall be
      allowed access to Biological Material solely for purposes of the
      collaboration and provided that it is bound by the same restrictions on
      use and transfer as LICENSEE under conditions outlined in Section 5.4.
      LICENSEE is only


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     Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.

      allowed to provide the mice under collaboration to 2 corporate partners.
      In addition, STANFORD will supply LICENSEE with 2 pairs of homozygous
      breeding mice and 4 pairs of heterozygote transgenic mice to begin
      research.

3.2   The term of said license shall commence as of the Effective Date of this
      Agreement and shall expire November 1, 2017 unless sooner terminated
      according to Article 9 hereunder.

3.3   STANFORD reserves the right to supply any or all of Biological Material to
      academic research scientists, subject to limitation of use by such
      scientists for research purposes only.

3.4   STANFORD will not file a patent application covering the Biological
      Material.

3.5   The Biological Material were made in the course of research conducted by
      Howard Hughes Medical Institute ("HHMI") in affiliation with Stanford
      University. LICENSEE acknowledges that STANFORD has granted to HHMI an
      irrevocable, nonexclusive, non-transferable, royalty-free license with
      respect to the Biological Materials.

3.6   LICENSEE agrees to take all action necessary on its part as LICENSEE to
      enable STANFORD to satisfy its reporting obligations to HHMI relating to
      Invention(s) and Biological Material as follows: "HHMI shall have the
      right to require periodic reporting, in confidence, on the utilization or
      efforts at obtaining utilization of any subject discovery or invention."

4.    ROYALTIES

4.1   LICENSEE agrees to pay to STANFORD a noncreditable, nonrefundable license
      issue royalty of [**]. Upon receipt of payment, STANFORD shall send a
      breeding pair of Biological Material to LICENSEE. LICENSEE shall not
      transfer Biological Material to any third party without prior written
      consent from STANFORD.

4.2   LICENSEE shall pay license maintenance royalties of [**] on November 7,
      1998, and [**] on every November 7 thereafter through November 7, 2017.
      Said payments are nonrefundable.

4.3   LICENSEE shall make a payment of [**] for each of the first two IND
      filings of products identified or discovered through material use of the
      Biological Material. LICENSEE shall not pay any more than [**] pursuant to
      this Section 4.3.

4.4   If LICENSEE should decide to make Biological Material available to a
      corporate partner under a collaboration as described in Section 3.1,
      LICENSEE will pay to STANFORD [**] upon transfer. This payment will be
      made for each collaborator who receives the mice.

4.5   All payments to STANFORD shall be in U.S. Dollars, net of any non-U.S.
      taxes.


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4.6   No other payments are due under this Agreement to STANFORD with regard to
      the Biological Material or products identified or discovered through the
      use of the Biological Material.

5.    NEGATION OF WARRANTIES

5.1   Nothing in this Agreement shall be construed as:

            (a)   A warranty or representation that anything made, used, sold,
                  or otherwise disposed of under any license granted in this
                  Agreement is or will be free from infringement of patents,
                  copyrights, and trademarks, of third parties;

            (b)   Conferring rights to use in advertising, publicity, or
                  otherwise any trademark or the name of "STANFORD"; or

            (c)   Granting by implication, estoppel, or otherwise any licenses
                  or rights under patents of STANFORD.

5.2   Except as expressly set forth in this Agreement, STANFORD makes no
      representations and extends no warranties of any kind, either express or
      implied. There are no express or implied warranties of merchantability or
      fitness for a particular purpose, or that the use of the Licensed
      Product(s) will not infringe any patent, copyright, trademark or other
      rights or any other . express or implied warranties. As of the Effective
      Date, STANFORD is unaware of any patents or other rights which cover the
      Biological Material.

5.3   LICENSEE agrees that nothing in this Agreement grants LICENSEE any express
      or implied license or right under or to: U.S. Patent 4,656,134,
      "Amplification of Eucaryotic Genes," or any patent application
      corresponding thereto.

6.    INDEMNITY

6.1   LICENSEE agrees to indemnify, hold harmless, and defend STANFORD, Stanford
      Health Services and Howard Hughes Medical Institute and their respective
      trustees, officers, employees, students, and agents against any and all
      claims for death, illness, personal injury, property damage, and improper
      business practices arising out of the use of Biological Material by
      LICENSEE or for any breach of this Agreement by LICENSEE, unless due to
      the gross negligence or willful misconduct of STANFORD. STANFORD shall
      promptly notify LICENSEE of such claim, other than any claim for breach of
      this Agreement by LICENSEE, and to the extent that the LICENSEE is
      responsible for payment to a third party under this indemnity, LICENSEE
      shall manage and control the defense and/or settlement of said
      indemnifiable claim, utilizing attorney's reasonably acceptable to
      STANFORD and HHMI. LICENSEE agrees not to settle any such claim against
      any Indemnitee without STANFORD's and HHMI's written consent where such
      settlement would include any admission of liability on the part of any
      Indemnitee, where the settlement would impose any restriction on the
      conduct by the Indemnitee of any of its activities, or where the
      settlement would not include an unconditional release of such Indemnitee
      from all liability for claims that are the subject matter of such claim.
      This Section 6.1 shall survive termination of this Agreement.


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6.2   Neither STANFORD nor Howard Hughes Medical Institute shall be liable for
      any indirect, special, consequential, or other damages whatsoever, whether
      grounded in tort (including negligence), strict liability, contract, or
      otherwise arising out of the use of Biological Material by LICENSEE,
      unless due to the gross negligence and willful misconduct of STANFORD.

6.3   LICENSEE shall at all times comply, through insurance or self-insurance,
      with all statutory workers' compensation and employers' liability
      requirements covering any and all employees with respect to activities
      performed under this Agreement.

7.    STANFORD NAMES AND MARKS

Except as required by law, LICENSEE agrees not to identify STANFORD in any
promotional advertising or other promotional Material(s) to be disseminated to
the public or any portion thereof or to use the name of any STANFORD faculty
member, employee, or student or any trademark, service mark, trade name, or
symbol of STANFORD or the Stanford Health Services, or that is associated with
either of them, without STANFORD's prior written consent, which shall not be
unreasonably withheld.

8.    TERMINATION

8.1   LICENSEE may terminate this Agreement for any reason and at any time by
      giving STANFORD notice in writing at least ninety (90) days in advance of
      the Effective Date of termination provided that LICENSEE shall thereupon
      cease use of Biological Material.

8.2   STANFORD may terminate this Agreement if LICENSEE is in material breach of
      any provision hereof; and LICENSEE fails to remedy any such breach within
      thirty (30) days after written notice thereof by STANFORD.

8.3   Surviving any termination are:

            (a)   Any cause of action or claim of LICENSEE or STANFORD, accrued
                  or to accrue, because of any breach by the other party;

            (b)   Payment of royalties due under Section 4 hereof; and

            (c)   The provisions of Articles 5 and 7.

8.4   At STANFORD's request, LICENSEE will return all Biological Material in its
      possession upon the effective date of termination of this Agreement.

9.    ASSIGNMENT

This Agreement may not be assigned except by LICENSEE to a party which acquires
all of substantively all of the business to which the Agreement relates through
a merger or sale of assets or otherwise.


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10.   MISCELLANEOUS

10.1  LICENSEE agrees to make written reports annually on or about November 1
      until the expiration of this license on November 1, 2017. These reports
      should contain a brief description of LICENSEE's use of Biological
      Material during the preceding year and shall be held by STANFORD in
      confidence.

10.2  Arbitration - If a controversy should arise out of this Agreement, or the
      breach thereof, the individuals executing this Agreement on behalf of each
      party, or their respective successors or designees (hereinafter referred
      to as "the parties") will provide written notice of the existence and
      nature of the dispute to each other and will attempt in good faith to
      resolve the dispute informally through discussion, the exchange of
      documents, or meetings. If the parties are unable to resolve the dispute
      informally within thirty (30) days after the date of the initial written
      notice to a party informing the party of a dispute, the parties may agree
      in writing to submit the dispute to arbitration in accordance with the
      Licensing Agreement Arbitration Rules of the American Arbitration
      Association. If the parties are unable to resolve the dispute informally
      within thirty (30) days after the date of the initial written notice of
      the dispute, either party may elect not to arbitrate the dispute and to
      file instead a civil action in a court of competent jurisdiction. These
      provisions shall not apply to HHMI's right to indemnification under this
      Agreement.

10.3  Termination Report - LICENSEE also agrees to make a written report to
      STANFORD within ninety (90) days after the date of termination of this
      Agreement, stating in such report the number and description of all
      Biological Material made or otherwise disposed of which were not
      previously reported to STANFORD.

10.4  Notices - All notices under this Agreement shall be deemed to have been
      fully given when done in writing and deposited in the United States mail,
      registered or certified, and addressed as follows:

                               To STANFORD:     Office of Technology Licensing
                                                Stanford University
                                                900 Welch Road, Suite 350
                                                Palo Alto, CA 94304-1850

                                                Attention: Director

                              To LICENSEE:      Ontogeny
                                                45 Moulton Street
                                                Cambridge, MA 02138-1118

                                                Attention:  ____________________

Either party may change its address upon written notice to the other party.

10.5  None of the terms of this Agreement can be waived except by the written
      consent of the party waiving compliance.


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10.6  This Agreement shall be governed by the laws of the State of California
      applicable to agreements negotiated, executed, and performed wholly within
      California.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement in duplicate
originals by their duly authorized officers or representatives.

       THE BOARD OF TRUSTEES OF THE LELAND
       STANFORD JUNIOR UNIVERSITY

       Signature:       /s/
                   ----------------------------------
       Name:
             ----------------------------------------
       Title:  Director, Technology Licensing
       Date:
             ----------------------------------------


       ONTOGENY, INC.

       Signature:  /s/
                   ----------------------------------
       Name:
             ----------------------------------------
       Title:
             ----------------------------------------
       Date:
             ----------------------------------------


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