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                                                                   Exhibit 10.16

                           SUBLEASE
[CB RICHARD ELLIS LOGO]      CB RICHARD ELLIS, INC
                           BROKERAGE AND MANAGEMENT
                           LICENSED REAL ESTATE BROKER

1.       PARTIES.

         This Sublease, dated December 29, 1999, 1999, is made between COR
         Therapeutics, Inc., a Delaware Corporation ("Sublessor"). and
         Cytokinetics (Sublessee").

2.       MASTER LEASE.

         Sublessor is the lessee under a written lease dated September 23, 1988,
         wherein Brittania Pointe Grand Limited Partnership, a Delaware limited
         partnership ("Lessor") leased to Sublessor the real property located in
         the City of South San Francisco, County of San Mateo, State of
         California described as +/- 125,545 square feet of office and
         laboratory space within the larger project of Brittania Pointe Grand.
         ("Master Premises"). Said lease has been amended by the following
         amendments One through eleven; said lease and amendments are herein
         collectively referred to as the "Master Lease" and are attached hereto
         as Exhibit "A."

3.       PREMISES.

         Sublessor hereby subleases to Sublessee on the terms and conditions set
         forth in this Sublease the following portion of the Master Premises
         ("Premises"): Initial premises : +/- 3,213 sq. ft. as shown on Exhibit
         A attached Additional premises: +/- 6,900 sq. ft. as shown in Exhibit A
         attached.

4.       WARRANTY BY SUBLESSOR.

         Sublessor warrants and represents to Sublessee that the Master Lease
         has not been amended or modified except as expressly set forth herein,
         that Sublessor is not now, and as of the commencement of the Term
         hereof will not be, in default or breach of any of the provisions of
         the Master Lease, and that Sublessor has no knowledge of any claim by
         Lessor that Sublessor is in default or breach of any of the provisions
         of the Master Lease.

5.       TERM.

         The Term of this Sublease shall commence * for the initial premises on
         January 1, 2000 * ("Commencement Date"), or when Lessor consents to
         this Sublease (if such consent is required under the Master Lease),
         whichever shall last occur, and end on December 31, 2000 ("Termination
         Date"), unless otherwise sooner terminated in accordance with the
         provisions of this Sublease. In the event the Term commences on a date
         other than the Commencement Date, Sublessor and Sublessee shall execute
         a memorandum setting forth the actual date of commencement of the Term.
         Possession of the Premises ("Possession") shall be delivered to
         Sublessee on the commencement of the Term. If for any reason Sublessor
         does not deliver Possession to Sublessee on the commencement of the
         Term, Sublessor shall not be subject to any liability for such failure,
         the Termination Date shall not be extended by the delay, and the
         validity of this Sublease shall not be impaired, but rent shall abate
         until delivery of Possession. Notwithstanding the foregoing, if
         Sublessor has not delivered Possession to Sublessee within thirty (30)
         days after the Commencement Date, then at any time thereafter and
         before delivery of Possession, Sublessee may give written notice to
         Sublessor of Sublessee's intention to cancel this Sublease. Said notice
         shall set forth an effective date for such cancellation which shall be
         at least ten (10) days after delivery of said notice to Sublessor. If
         Sublessor delivers Possession to Sublessee on or before such effective
         date, this Sublease shall remain in full force and effect. If Sublessor
         fails to deliver Possession to Sublessee on or before such effective
         date, this Sublease shall be cancelled, in which case all consideration
         previously paid by Sublessee to Sublessor on account of this Sublease
         shall be returned to Sublessee, this Sublease shall thereafter be of no
         further force or effect, and Sublessor shall have no further liability
         to Sublessee on account of such delay or cancellation. If Sublessor
         permits Sublessee to take Possession prior to the commencement of the
         Term, such early Possession shall not advance the Termination Date and
         shall be subject to the provisions of this Sublease, including without
         limitation the payment of rent.

         * and April 1, 2000 for the additional premises.

6.       RENT.

         6.1      Minimum Rent.* Sublessee shall pay to Sublessor as minimum
                  rent, without deduction, setoff, notice, or demand, at 256 E.
                  Grand Avenue, South San Francisco, CA 94080 or at such other
                  place as Sublessor shall designate from time to time by notice
                  to Sublessee, the sum of _________ Dollars ($__________) per
                  month, in advance on the first day of each month of the Term.
                  Sublessee shall pay to Sublessor upon execution of this
                  Sublease the sum of Six thousand five hundred ninety-four and
                  55/100 Dollars ($ 6594.55) as rent for the first month of the
                  lease term. If the Term begins or ends on a day other than the
                  first or last day of a month, the rent for the partial months
                  shall be prorated on a per diem basis. Additional provisions:
                           See addendum attached.

         6.2      Operating Costs. If the Master Lease requires Sublessor to pay
                  to Lessor all or a portion of the expenses of operating the
                  building and/or project of which the Premises are a part
                  ("Operating Costs"), including but not limited to taxes,
                  utilities, or insurance, then Sublessee shall pay to Sublessor
                  as additional rent two and seven tenths percent ( 2.7 %) of
                  the amounts payable by Sublessor for Operating Costs incurred
                  during the Term. Such

                  * based on the initial premises, and 8.1% (eight and one tenth
                  percent) beginning April 1, 2000 inclusive of the initial and
                  additional premises.

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                  additional rent shall be payable as and when Operating Costs
                  are payable by Sublessor to Lessor. If the Master Lease
                  provides for the payment by Sublessor of Operating Costs on
                  the basis of an estimate thereof, then as and when adjustments
                  between estimated and actual Operating Costs are made under
                  the Master Lease, the obligations of Sublessor and Sublessee
                  hereunder shall be adjusted in a like manner; and if any such
                  adjustment shall occur after the expiration or earlier
                  termination of the Term, then the obligations of Sublessor and
                  Sublessee under this Subsection 6.2 shall survive such
                  expiration or termination. Sublessor shall, upon request by
                  Sublessee, furnish Sublessee with copies of all statements
                  submitted by Lessor of actual or estimated Operating Costs
                  during the Term.

7.       SECURITY DEPOSIT.

         Sublessee shall deposit with Sublessor upon execution of this Sublease
         the sum of twenty thousand and 00/100 dollars Dollars ($ 20,000,00) as
         security for Sublessee's faithful performance of Sublessee's
         obligations hereunder ("Security Deposit"). If Sublessee fails to pay
         rent or other charges when due under this Sublease, or fails to perform
         any of its other obligations hereunder, Sublessor may use or apply all
         or any portion of the Security Deposit for the payment of any rent or
         other amount then due hereunder and unpaid, for the payment of any
         other sum for which Sublessor may become obligated by reason of
         Sublessee's default or breach, or for any loss or damage sustained by
         Sublessor as a result of Sublessee's default or breach. If Sublessor so
         uses any portion of the Security Deposit, Sublessee shall, within ten
         (10) days after written demand by Sublessor, restore the Security
         Deposit to the full amount originally deposited, and Sublessee's
         failure to do so shall constitute a default under this Sublease.
         Sublessor shall not be required to keep the Security Deposit separate
         from its general accounts, and shall have no obligation or liability
         for payment of interest on the Security Deposit. In the event Sublessor
         assigns its interest in this Sublease, Sublessor shall deliver to its
         assignee so much of the Security Deposit as is then held by Sublessor.
         Within ten (10) days after the Term has expired, or Sublessee has
         vacated the Premises, or any final adjustment pursuant to Subsection
         6.2 hereof has been made, whichever shall last occur, and provided
         Sublessee is not then in default of any of its obligations hereunder,
         the Security Deposit, or so much thereof as had not theretofore been
         applied by Sublessor, shall be returned to Sublessee or to the last
         assignee, if any, of Sublessee's interest hereunder.

8.       USE OF PREMISES.

         The Premises shall be used and occupied only for general office,
         administrative, and related legal uses., ______________and for no other
         use or purpose.

9.       ASSIGNMENT AND SUBLETTING.

         Sublessee shall not assign this Sublease or further sublet all or any
         part of the Premises without the prior written consent of Sublessor
         (and the consent of Lessor, if such is required under the terms of the
         Master Lease).

10.      OTHER PROVISIONS OF SUBLEASE.

         All applicable terms and conditions of the Master Lease are
         incorporated into and made a part of this Sublease as if Sublessor were
         the lessor thereunder, Sublessee the lessee thereunder, and the
         Premises the Master Premises, except for the following:

         ______________________________________________________________________
         ______________________________________________________________________
         ______________________________________________________________________.

         Sublessee assumes and agrees to perform the lessee's obligations under
         the Master Lease during the Term to the extent that such obligations
         are applicable to the Premises, except that the obligation to pay rent
         to Lessor under the Master Lease shall be considered performed by
         Sublessee to the extent and in the amount rent is paid to Sublessor in
         accordance with Section 6 of this Sublease. Sublessee shall not commit
         or suffer any act or omission that will violate any of the provisions
         of the Master Lease. Sublessor shall exercise due diligence in
         attempting to cause Lessor to peform its obligations under the Master
         Lease for the benefit of Sublessee. If the Master Lease terminates,
         this Sublease shall terminate and the parties shall be relieved of any
         further liability or obligation under this Sublease, provided however,
         that if the Master Lease terminates as a result of a default or breach
         by Sublessor or Sublessee under this Sublease and/or the Master Lease,
         then the defaulting party shall be liable to the nondefaulting party
         for the damage suffered as a result of such termination.
         Notwithstanding the foregoing, if the Master Lease gives Sublessor any
         right to terminate the Master Lease in the event of the partial or
         total damage, destruction, or condemnation of the Master Premises or
         the building or project of which the Master Premises are a part, the
         exercise of such right by Sublessor shall not constitute a default or
         breach hereunder.

11.      ATTORNEYS' FEES.

         If Sublessor, Sublessee, or Broker shall commence an action against the
         other arising out of or in connection with this Sublease, the
         prevailing party shall be entitled to recover its costs of suit and
         reasonable attorney's fees.

14.      NOTICES.

         All notices and demands which may or are to be required or permitted to
         be given by either party on the other hereunder shall be in writing.
         All notices and demands by the Sublessor to Sublessee shall be sent by
         United States Mail, postage prepaid, addressed to the Sublessee at the
         Premises, and to the address hereinbelow, or to such other place as
         Sublessee may from

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         time to time designate in a notice to the Sublessor. All notices and
         demands by the Sublessee to Sublessor shall be sent by United States
         Mail, postage prepaid, addressed to the Sublessor at the address set
         forth herein, and to such other person or place as the Sublessor may
         from time to time designate in a notice to the Sublessee.

         To Sublessor: 256 E. Grand Avenue, South San Francisco, CA 94080

         To Sublessor: 280 E. Grand Avenue, South San Francisco, CA 94080

15.      CONSENT BY LESSOR.

         THIS SUBLEASE SHALL BE OF NO FORCE OR EFFECT UNLESS CONSENTED TO BY
         LESSOR WITHIN 10 DAYS AFTER EXECUTION HEREOF, IF SUCH CONSENT IS
         REQUIRED UNDER THE TERMS OF THE MASTER LEASE.

16.      COMPLIANCE.

         The parties hereto agree to comply with all applicable federal, state
         and local laws, regulations, codes, ordinances and administrative
         orders having jurisdiction over the parties, property or the subject
         matter of this Agreement, including, but not limited to, the 1964 Civil
         Rights Act and all amendments thereto, the Foreign Investment In Real
         Property Tax Act, the Comprehensive Environmental Response Compensation
         and Liability Act, and The Americans With Disabilities Act.

Sublessor: COR Therapeutics, Inc.          Sublessee: Cytokinetics, Inc.
           ____________________________               __________________________

By:  /s/ Peter S. Roddy                    By:  /s/ Robert J. Blum
    ___________________________________        _________________________________

Title:  VP Finance                         Title: VP Business Development
       ________________________________           ______________________________

By: ___________________________________    By: _________________________________

Title: ________________________________    Title: ______________________________

Date: _________________________________    Date: _______________________________

                          LESSOR'S CONSENT TO SUBLEASE

The undersigned ("Lessor"), lessor under the Master Lease, hereby consents to
the foregoing Sublease without waiver of any restriction in the Master Lease
concerning further assignment or subletting. Lessor certifies that, as of the
date of Lessor's execution hereof, Sublessor is not in default or breach of any
of the provisions of the Master Lease, and that the Master Lease has not been
amended or modified except as expressly set forth in the foregoing Sublease.

Lessor:____________________________________

By:________________________________________

Title: ____________________________________

By: _______________________________________

Title: ____________________________________

Date: _____________________________________

         CONSULT YOUR ADVISORS - This document has been prepared for approval by
         your attorney. No representation or recommendation is made by Broker as
         to the legal sufficiency or tax consequences of this document or the
         transaction to which it relates. These are questions for your attorney.

         In any real estate transaction, it is recommended that you consult with
         a professional, such as a civil engineer, industrial hygienist or other
         person, with experience in evaluating the condition of the property,
         including the possible presence of asbestos, hazardous materials and
         underground storage tanks.

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                              ADDENDUM TO SUBLEASE
           BETWEEN COR THERAPEUTICS, INC., A DELAWARE CORPORATION AND
                               CYTOKINETICS, INC.
                             DATED DECEMBER 29, 1999

17.      MINIMUM RENT SCHEDULE:

         January 1, 2000 to March 31, 2000:                $ 6594.55 per month
         April 1, 2000 to October 31, 2000:                $ 17,979.55 per month
         November 1, 2000 to December 30, 2000:            $ 18,698.73 per month

18.      EXTENSION OPTION

         Sublessee shall have the right to extend the sublease term by an
         additional six (6) months provided Sublessee has not been in default of
         any of the terms and conditions of this Sublease. The extension option
         shall be exercised in writing to Sublessor no later than September 30,
         2000. Sublessee's occupancy of the premises after June 30, 2001 shall
         be considered a month-to-month tenancy and subject to the right of
         either party to terminate this Sublease with ninety (90) days written
         notice.

19.      CONDITION OF PREMISES

         Sublessee agrees to accept the premises in as-is condition. Sublessor
         shall not be responsible for any maintenance, repairs, or improvements
         to the premises.

                                                             Initials:
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