UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                                 SCHEDULE 13D

                   UNDER THE SECURITIES EXCHANGE ACT OF 1934

                               (AMENDMENT NO. 0)

                               PROGENITOR, INC.
                               (Name of Issuer)

                         COMMON STOCK, $.001 PAR VALUE
                        (Title of Class of Securities)

                                  00075888F1
                                (CUSIP Number)

                           George A. Vandeman, Esq,
                            Senior Vice President,
                         General Counsel and Secretary
                                  Amgen Inc.
                                 Amgen Center
                            1840 DeHavilland Drive
                         Thousand Oaks, CA 91320-1789
                                (805) 447-1000

                 (Name, Address and Telephone Number of Person
               Authorized to Receive Notices and Communications)


                                August 12, 1997
                     (Date of Event which Requires Filing
                              of this Statement)

if the filing person has previously filed a statement on Schedule 13G to report 
the acquisition which is the subject of this Schedule 13D, and is filing this 
schedule because of Rule 13d- 1(b)(3) or (4), check the following / /.

Check the following box if a fee is being paid with the statement. / / (A fee is
not required only if the reporting person: (1) has a previous statement on file 
reporting beneficial ownership of more than five percent of the class of 
securities described in Item 1; and (2) has filed no amendment subsequent 
thereto reporting beneficial ownership of five percent or less of such class.) 
(See Rule 13d-7.)

NOTE: Six copies of this statement, including all exhibits, should be filed with
the Commission. SEE Rule 13d-1(a) for other parties to whom copies are to be 
sent.

*The remainder of this cover page shall be filled out for a reporting person's 
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter 
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

 
                                 SCHEDULE 13D

  CUSIP NO. 00075888F1                                       PAGE 2 OF 5 PAGES
 
- ------------------------------------------------------------------------------
      NAME OF PERSON
 1       AMGEN INC.
- ------------------------------------------------------------------------------
 2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) [_]
                                                                (b) [_]
- ------------------------------------------------------------------------------
 3    SEC USE ONLY
- ------------------------------------------------------------------------------
 4    SOURCE OF FUNDS*
         WC
- ------------------------------------------------------------------------------
 5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS               [_]
      REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)
- ------------------------------------------------------------------------------
 4    CITIZENSHIP OR PLACE OF ORGANIZATION
         DELAWARE
- ------------------------------------------------------------------------------
                     7    SOLE VOTING POWER
     NUMBER OF              1,023,256
      SHARES       -----------------------------------------------------------
   BENEFICIALLY      8    SHARED VOTING POWER
     OWNED BY               N/A
       EACH        -----------------------------------------------------------
    REPORTING        9    SOLE DISPOSITIVE POWER 
      PERSON                1,023,256
       WITH        ---------------------------------------------------------
                     10   SHARED DISPOSITIVE POWER
                            N/A
- ------------------------------------------------------------------------------
 11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH
     REPORTING PERSON
       1,023,256
- ------------------------------------------------------------------------------
 12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)                  [_]
     EXCLUDES CERTAIN SHARES*              
       N/A
- ------------------------------------------------------------------------------
 13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
       7.7
- ------------------------------------------------------------------------------
      
 14  TYPE OF REPORTING PERSON *
       CO
- ------------------------------------------------------------------------------
                     *SEE INSTRUCTION BEFORE FILLING OUT 



 
ITEM 1.  SECURITY AND ISSUER.

       This Schedule 13D (the "Schedule 13D") is being filed by Amgen Inc., a
Delaware corporation, to report Amgen Inc.'s acquisition of One Million Twenty-
three Thousand Two Hundred Fifty-six (1,023,256) shares (the "Shares") of the
common stock, $.001 par value per share (the "Common Stock") of Progenitor,
Inc., a Delaware corporation (the "Issuer"). The principal executive offices of
the Issuer are located at 1507 Chambers Road, Columbus, Ohio 43212.


ITEM 2.  IDENTITY AND BACKGROUND.

       (a)-(c). This statement is being filed by Amgen Inc., a Delaware
corporation (the "Reporting Person"). The Reporting Person is a global
biotechnology company that discovers, develops, manufactures and markets human
therapeutics based upon advances in cellular and molecular biology. Its
principal business and principal offices are located at Amgen Center, 1840
DeHavilland Drive, Thousand Oaks, California 91320-1789.

       For information with respect to the identity and background of each
executive officer and director of the Reporting Person, see Schedule I attached
hereto.

       (d)-(e).  During the last five years, neither the Reporting Person nor,
to the best knowledge of the Reporting Person, none of the other persons
identified in Schedule I:  (i) have been convicted in a criminal proceeding
(excluding traffic violations or similar misdemeanors); or (ii) was a party to a
civil proceeding of a judicial or administrative body of competent jurisdiction
and as a result of such proceeding was or is subject to a judgment, decree or
final order enjoining future violations of, or prohibiting or mandating
activities subject to, federal or state securities laws or finding any violation
with respect to such laws.


ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

       The source of the $5,500,186.05 used for the Reporting Person's purchase
(as described in Item 5(c) below) of 1,023,256 shares of Common Stock was
comprised of $4,500,186.05 from the working capital of the Reporting Person and
a $1,000,000 Non-negotiable Promissory Note dated as of August 12, 1997 by and
between the Reporting Person and the Issuer (the "Promissory Note") payable in
two equal payments on December 31, 1997 and December 31, 1998, respectively,
from the working capital of the Reporting Person.


ITEM 4.  PURPOSE OF TRANSACTION.

       The Reporting Person acquired the 1,023,256 shares of Common Stock for
investment purposes.

       As a result of a December 31, 1996 Stock Purchase Agreement by and
between the Reporting Person and the Issuer, further described in Item 6 below,
the Reporting Person is subject to a number of so-called "standstill"
restrictions (the "Standstill Restrictions").  One Standstill Restriction
generally prohibits the Reporting Person from 

                                       1

 
acquiring an amount equal to or more than 10% of the then total voting power of
the Issuer (calculated in accordance with Rule 13d-3 under the Exchange Act).
Other Standstill Restrictions generally prohibit the Reporting Person from
making acquisition proposals to the Issuer and engaging in the solicitation of
proxies. SEE Item 6, below, for additional information with respect to the
Standstill Restrictions. ALSO SEE Item 6, below, for a discussion of certain (i)
restrictions on sale of any Common Stock held by the Reporting Person, including
the Shares, (ii) registration rights with respect to the Common Stock
beneficially owned by the Reporting Person, and (iii) a right of first purchase
of the Common Stock beneficially owned by the Reporting Person.

       Subject to the Standstill Restrictions, sales restrictions or the right
of first purchase and depending on general market and economic conditions
affecting the Issuer and other relevant factors, the Reporting Person may
purchase additional shares of Common Stock or dispose of some or all of its
shares of Common Stock from time to time in open market transactions, private
transactions or otherwise.

       Except as set forth in this Schedule 13D, the Reporting Person has no
present plans or proposals with respect to any material change in the Issuer's
business or corporate structure or which relate to or would result in:

       (1) the acquisition by any person of additional securities of the Issuer,
   or the disposition of securities of the Issuer;

       (2) an extraordinary corporate transaction, such as a merger,
   reorganization or liquidation, involving the Issuer or any of its
   subsidiaries;

       (3) a sale or transfer of a material amount of assets of the Issuer or
   any of its subsidiaries;

       (4) any change in the present board of directors or management of the
   Issuer, including any plans or proposals to change the number or term of
   directors or to fill any existing vacancies on the board;

       (5) any material change in the present capitalization or dividend policy
   of the Issuer;

       (6) any other material change in the Issuer's business or corporate
   structure;

       (7) changes in Issuer's charter, bylaws or instruments corresponding
   thereto or other actions which may impede the acquisition of control of the
   Issuer by any person;

       (8) causing a class of securities of the Issuer to be delisted from a
   national securities exchange or cease to be authorized to be quoted in an
   inter-dealer quotation system of a registered national securities
   association;

       (9) a class of equity securities of the Issuer becoming eligible for
   termination of registration pursuant to Section 12(g)(4) of the Securities
   Exchange Act of 1934; or

       (10) any action similar to any of those enumerated above.

                                       2

 
ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER.

   (a) As of the close of business on August 12, 1997, the Reporting Person
beneficially owned 1,023,256 shares of Common Stock. The Shares of Common Stock
constitute approximately 7.7% of the total number of shares of Common Stock
outstanding as of August 12, 1997.

   (b) The Reporting Person has the sole power to vote or to direct the vote
with respect to, and the sole power to dispose or to direct the disposition of,
the Shares beneficially owned by the Reporting Person

   (c) On August 12, 1997, the Reporting Person  acquired from the Issuer in a
private transaction 1,023,256 shares of Common Stock, for a total purchase price
of $5,500,186.05.

   (d) Not applicable.

   (e) Not applicable.


ITEM 6.  CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT
         TO SECURITIES OF THE ISSUER

       Pursuant to a Stock Purchase Agreement dated as of December 31, 1996, by
and between the Issuer and the Reporting Person (the "Purchase Agreement"), the
Reporting Person acquired from the Issuer concurrent with the closing of the
Issuer's Initial Public Offering on August 12, 1997, 1,023,256 shares of Common
Stock, for a total purchase price of $5,500,186.05.

       Section 8 of the Purchase Agreement also contains the Standstill
Restrictions referred to in Item 4.  The Reporting Person has agreed, among
other things, for a period of 3 years or the time at which the Reporting Person
cease to hold more than 2 1/2% of the voting securities of the Issuer or when a
third party gains significant control of the Issuer, whichever is earlier, (i)
not to purchase any shares of the capital stock of the Issuer if its ownership
position in the Issuer would be equal to or greater than 10% of the then total
voting power of the Issuer (calculated in accordance with Rule 13d-3 under the
Exchange Act), (ii) not to engage in the solicitation of proxies and (iii) not
to make any acquisition proposals.  There are certain limited circumstances in
which the Standstill Restrictions would not apply.

       The Reporting Person also has agreed that for a period of 180 days after
the Issuer's Initial Public Offering, which closed as of August 12, 1997, it
would not sell the Shares.

       The Issuer has also granted the Reporting Person customary demand and
piggyback registration rights under Section 5 of the Purchase Agreement with
respect to the Shares. Pursuant to a letter of agreement regarding stock
transfer restrictions entered into by and between the Issuer and the Reporting
Person as of August 6, 1997 (the "Letter Agreement") which modifies the Purchase
Agreement, the Reporting Person may request a demand registration in advance of
that date that is six (6) months after the Issuer's Initial Public Offering (the
"Six Month Anniversary"). Pursuant to Section 1.1 of the Letter Agreement, upon
receipt of such notice, the Issuer is required to use its reasonable efforts to
file a registration statement with the Securities and Exchange Commission at
least forty-five (45) days prior to the Six Month Anniversary date and to cause
such registration statement to become effective on or prior to the Six Month
Anniversary date.

       Section 4.1 of the Purchase Agreement also provides the Issuer with a
right of first purchase with respect to the Shares which the Reporting Person
proposes to sell pursuant to the registration rights set forth in Section 5 of
the Purchase Agreement.

                                       3

 
       The above description of the Purchase Agreement and the Letter Agreement,
as well as the description of the Purchase Agreement set forth in Item 4 and the
Promissory Note set forth in Item 3, are summaries only and do not purport to be
complete descriptions of the terms of such Purchase Agreement, such Letter
Agreement and such Promissory Note. These summaries are subject to, and are
qualified in their entirety by reference to, the detailed provisions of the
Purchase Agreement and the Promissory Note, which are filed as exhibits to this
Schedule 13D.


ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS.

7.1    Stock Purchase Agreement, dated as of December 31, 1996, by and between
       the Issuer and the Reporting Person. (Incorporated by reference herein
       from the Form S-1 filed with the Securities and Exchange Commission by
       the Issuer on July 29, 1997.)

7.2    Non-negotiable Promissory Note, dated as of August 12, 1997, by and
       between the Issuer and the Reporting Person.

7.3    Agreement Regarding Stock Transfer Restrictions, dated as of August 6,
       1997, by and between the Issuer and the Reporting Person.

                                   SIGNATURE

       After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


AMGEN INC.

/s/ George A. Vandeman
_______________________________
Name:  George A. Vandeman
Title: Senior Vice President, General
       Counsel and Secretary


Dated:  August 22, 1997


                                       4

 
                                 EXHIBIT INDEX
                                 -------------



Exhibit Number                   Description
- --------------                   -----------

  7.1               Stock Purchase Agreement dated as of December 31, 1996, by
                    and between Amgen Inc. and Progenitor, Inc. (Incorporated by
                    reference herein from the Form S-1 filed with the Securities
                    and Exchange Commission by Progenitor, Inc. on July 29,
                    1997.)

  7.2               Non-negotiable Promissory Note, dated as of August 12, 1997,
                    by and between Amgen Inc. and Progenitor, Inc.

  7.3               Agreement Regarding Stock Transfer Restrictions, dated as of
                    August 6, 1997, by and between Progenitor, Inc. and Amgen 
                    Inc.

 
                                   SCHEDULE I

                                   AMGEN INC.
                        EXECUTIVE OFFICERS AND DIRECTORS

                               EXECUTIVE OFFICERS
Name Present Business Address Present Principal Occupation - ---- ------------------------ ---------------------------- N. Kirby Alton Amgen Inc. Senior Vice President, Development Amgen Center 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Robert S. Attiyeh Amgen Inc. Senior Vice President, Finance and Amgen Center Corporate Development 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Stan Benson Amgen Inc. Senior Vice President, Sales Amgen Center and Marketing 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Gordon M. Binder Amgen Inc. Chairman of the Board and Amgen Center Chief Executive Officer 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Dennis M. Fenton Amgen Inc. Senior Vice President, Operations Amgen Center 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Daryl D. Hill Amgen Inc. Senior Vice President, Quality Amgen Center and Compliance 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Kevin W. Sharer Amgen Inc. President and Chief Operating Officer Amgen Center 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Lawrence M. Souza Amgen Inc. Senior Vice President, Research Amgen Center 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 George A. Vandeman Amgen Inc. Senior Vice President, General Amgen Center Counsel and Secretary 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789
EMPLOYEE DIRECTORS ------------------
Name Present Business Address Present Principal Occupation - ---- ------------------------ ---------------------------- Gordon M. Binder Amgen Inc. Chairman of the Board and Amgen Center Chief Executive Officer, Amgen 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789 Kevin W. Sharer Amgen Inc. President and Chief Operating Officer, Amgen Center Amgen 1840 DeHavilland Drive Thousand Oaks, CA 91320-1789
NON EMPLOYEE DIRECTORS ----------------------
Name Present Business Address Present Principal Occupation - ---- ------------------------ ---------------------------- William K. Bowes, Jr. U.S. Venture Partners General Partner, U.S. Venture Partners 2180 Sand Hill Road, Suite 300 Menlo Park, CA 94025 Franklin P. Johnson, Jr. Asset Management Partners General Partner, Asset Management 2275 East Bayshore Road, Suite 150 Partners Palo Alto, CA 94303 Steven Lazarus ARCH Venture Partners, L.P. Managing Director, ARCH Venture Partners, L.P. O'Hare Plaza 8735 West Higgins Road, Suite 235 Chicago, IL 60631 Edward J. Ledder Medicine Bow River Ranch Retired Chairman of the Board and P. O. Box 410 Chief Executive Officer, Abbott Medicine Bow, WY 82329 Laboratories Gilbert S. Omenn University of Washington Dean, School of Public Health and Dean's Office, School of Public Community Medicine, University of Health & Community Medicine Washington Box 357230 Seattle, WA 98195 Judith C. Pelham Mercy Health Services President and Chief Executive Officer, 34605 Twelve Mile Road Mercy Health Services Farmington Hills, MI 48331-3221

 
                                                                     EXHIBIT 7.2

                        NON-NEGOTIABLE PROMISSORY NOTE
                        ------------------------------

$1,000,000                                                       August 12, 1997

     FOR VALUE RECEIVED, the undersigned, Amgen Inc. (hereinafter referred to as
"Maker"), hereby promises to pay to the order of Progenitor, Inc. (hereinafter 
referred to as "Holder"), at the office of Holder at 1507 Chambers Road, 
Columbus, OH 43212-1566, Attention: Chief Financial Officer (or such other place
as Holder may direct from time to time), in lawful money of the United States 
and in immediately available funds, the principal sum of One Million Dollars 
($1,000,000) in accordance with the schedule set forth below.

     This Note is given pursuant to that certain Stock Purchase Agreement, dated
December 31, 1996, by and between Maker and Holder (the "Stock Purchase 
Agreement").

     Maker shall make payment under this Note in accordance with the following 
schedule:

     1.  On December 31, 1997, the principal amount of Five Hundred Thousand 
Dollars ($500,000), without interest; and

     2.  On December 31, 1998, the principal amount of Five Hundred Thousand 
Dollars ($500,000), without interest.

     Notwithstanding the foregoing payment schedule, if Maker should sell or 
otherwise transfer any of the 186,047 shares of Holder's Common Stock purchased 
by Maker pursuant to the Stock Purchase Agreement and referred to therein as the
Note Common Stock (the "Note Common Stock"), Maker shall repay to Holder on the 
date of such sale or transfer a principal amount equal to the greater of (i) the
portion of the outstanding principal balance under this Note that corresponds to
the portion of the Note Common Stock owned by Maker and so transferred or sold
or (ii) the proceeds of such transaction, up to the outstanding principal amount
of this Note.

     Any principal amount not paid as required by any date specified in this 
Note shall bear interest at a rate equal to the prime rate (or other commercial 
lending rate for borrowers of the highest credit standing) announced from time 
to time by Bank of America NT&SA, San Francisco, California, from the date due 
until the date of payment, and shall be due and payable upon the payment of such
principal.

     The entire unpaid principal balance may be prepaid, in whole or in part, at
any time without premium or penalty.

     Unless otherwise agreed by the holder, all payments on this Note shall be 
applied first to interest, if any, and then to the remaining principal.

     The remedies of Holder, as provided herein, shall be cumulative and 
concurrent, and may be pursued singularly, successively or together, at the sole
discretion of Holder, and may be exercised as often as the occasion therefor 
shall arise. No act of omission or commission of Holder, including specifically 
any failure to exercise any right, remedy or recourse, shall be deemed to be a 
waiver or release of the same, such waiver or release to be effected only 
through

 
a written document executed by Holder and then only to the extent specifically 
recited therein. A waiver or release with reference to any demand hereunder 
shall not be construed as continuing, as a bar to, or as a waiver or release of,
any subsequent right, remedy or recourse as to a subsequent demand.

        Maker's obligation to make payment under this Note is absolute and 
unconditional, and shall not be subject to any right of setoff, counterclaim or 
other defense that Maker may have against Holder or any other person or entity 
under applicable law or otherwise, including with respect to any claims, 
actions or rights arising under or in connection with the Stock Purchase 
Agreement, that certain License Agreement by and between Maker and Holder, dated
as of December 31, 1996, or any other agreement or document, whether arising by 
breach of representation, warranty, or covenant or otherwise.

        Maker hereby waives presentment and demand for payment, protest or 
notice of protest and non-payment of any kind.

        Maker promises to pay all reasonable collection expenses, court costs 
and attorneys' fees which may be incurred in connection with the collection or 
enforcement of this Note or any part thereof. 

        Holder may not transfer any of its rights under this Note without the 
prior written consent of Maker, which consent shall not be unreasonably 
withheld.

        Any provision of this Note that is illegal, invalid or unenforceable, 
shall be ineffective to the extent of such illegality, invalidity or 
unenforceability without rendering illegal, invalid or unenforceable the 
remaining provisions of this Note.

        This Note shall be governed by and construed in accordance with the laws
of the State of California without regard to conflict of laws principles.

                                 MAKER:

                                 AMGEN INC. 

                                 By: /s/ GEORGE A. VANDEMAN
                                     ------------------------------------------
                                 Name:  GEORGE A. VANDEMAN
                                        ---------------------------------------
                                 Title: Senior Vice President, General Counsel, 
                                        ---------------------------------------
                                        and Secretary   
                                        ---------------------------------------
                                               
                                              

                                                                     EXHIBIT 7.3

                               AGREEMENT REGARDING

                           STOCK TRANSFER RESTRICTIONS

     THIS AGREEMENT REGARDING STOCK TRANSFER RESTRICTIONS is entered into as of
August 6, 1997 by and between Progenitor, Inc., a Delaware corporation
("Progenitor") and Amgen Inc., a Delaware corporation ("Amgen").

     Progenitor and Amgen are parties to that certain Stock Purchase Agreement
dated December 31, 1996 (the "Stock Purchase Agreement"). Capitalized terms used
herein and not otherwise defined herein shall have the meanings as described in
the Stock Purchase Agreement.

     The parties intending to be legally bound and in consideration of the
mutual covenants and agreements of the parties herein contained, and other good
and valuable consideration the receipt and adequacy of which is hereby
acknowledged, hereby agree as follows:

1. CERTAIN AGREEMENTS

         1.1. REGISTRATION BY PROGENITOR.

         Amgen may provide notice to Progenitor requesting a demand registration
pursuant to Section 5.2 of the Stock Purchase Agreement in advance of that date
that is six (6) months after the Initial Public Offering (the "Six Months
Anniversary Date") and upon receipt of such notice the Company shall use its
reasonable efforts to file with the SEC at least forty-five (45)days prior to
the Six Months Anniversary Date pursuant to such Section 5.2 and use its
reasonable efforts to cause such registration statement to become effective on
or prior to the Six Months Anniversary Date and Progenitor shall maintain the
effectiveness thereof in accordance with the terms of the Stock Purchase
Agreement and shall also not terminate such effectiveness without first giving
Amgen at least thirty (30) days prior written notice.

         1.2. LOCK-UP AGREEMENTS.

         Progenitor has entered into lock-up agreements in the form attached
hereto as Exhibit 1 including the extension agreements in the form attached
hereto as part of such Exhibit 1 with each of the entities listed in Exhibits
2, 3, and 4 (respectively the "Interwest Investors", the "Robertson Stephens
Investors" and the "Oak Investors") and has entered into a lock-up agreement in
the form attached hereto as Exhibit 5 with Interneuron Pharmaceuticals, Inc.
("Interneuron").



 
     1.3.  WAIVER BY LEHMAN BROTHERS.

     Lehman Brothers has agreed with Progenitor on the terms and conditions 
contained in Exhibit 6 attached hereto and expressly for the benefit of 
Progenitor and Amgen that it shall not waive the lock-up restrictions applicable
to Interneuron, The Oak Investors, the Robertson Stephens Investors or the 
Interwest Investors without the prior written consent of Progenitor and Amgen.

2.  MISCELLANEOUS PROVISIONS

     2.1  GOVERNING LAW.

     This Agreement shall be construed in accordance with, and governed in all 
respects by, the internal laws of the State of Delaware (without giving effect 
to principles of conflicts of laws).

     2.2.  WAIVER.

     No party shall be deemed to have waived any power, right, privilege or 
remedy under this Agreement, unless the waiver of such claim, power, right, 
privilege or remedy is expressly set forth in a written instrument duly executed
and delivered on behalf of such party by an executive officer; and any such 
waiver shall not be applicable or have any effect except in the specific 
instance in which it is given.


 
     2.3.  COUNTERPARTS.

     This Agreement may be executed in several counterparts, each of which shall
constitute an original and all of which, when taken together, shall constitute 
one agreement.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be 
executed and delivered as of the date first written above.

                                            PROGENITOR, INC.

                                            By:
                                                ------------------------------
                                            Name:
                                                  ----------------------------
                                            Its:
                                                 -----------------------------


                                            AMGEN INC.

                                            By:
                                                ------------------------------
                                            Name:
                                                  ----------------------------
                                            Its:
                                                 -----------------------------