Exhibit 10.4

                        Millennium Pharmaceuticals, Inc.


                             Incentive Stock Option
                     GRANTED UNDER 2000 STOCK INCENTIVE PLAN

1. GRANT OF OPTION.

         This document evidences the grant by Millennium Pharmaceuticals, Inc.,
a Delaware corporation (the "Company"), on JULY 18, 2005 (the "Grant Date") to
Deborah Dunsire, an employee of the Company (the "Participant"), of an option to
purchase, in whole or in part, on the terms provided in this document and in the
Company's 2000 Stock Incentive Plan (the "Plan"), a total of 40,000 shares (the
"Shares") of common stock, $.001 par value per share, of the Company ("Common
Stock") at $10.00 per Share. Unless earlier terminated, this option shall expire
on JULY 18, 2015 (the "Final Exercise Date").

         It is intended that the option evidenced by this document shall be an
incentive stock option as defined in Section 422 of the Internal Revenue Code of
1986, as amended and any regulations promulgated thereunder (the "Code"). Except
as otherwise indicated by the context, the term "Participant," as used in this
option, shall be deemed to include any person who acquires the right to exercise
this option validly under its terms.

2. VESTING SCHEDULE.

         Subject to Section 3 below and applicable law, this option will become
exercisable ("vest") as follows:

         Twelve forty-eighths (12/48ths) of the total number of Shares subject
to this option shall become exercisable on July 18, 2006 and an additional one
forty-eighth (1/48th) of the total number of Shares subject to this option shall
become exercisable monthly thereafter until all of such Shares are exercisable.

         The right of exercise shall be cumulative so that to the extent the
option is not exercised in any period to the maximum extent permissible it shall
continue to be exercisable, in whole or in part, with respect to all Shares for
which it is vested until the earlier of the Final Exercise Date or the
termination of this option under Section 3 of this document or the Plan.

3. EXERCISE OF OPTION.

         (a) FORM OF EXERCISE. Each election to exercise this option shall be in
writing in the form attached to this document, signed by the Participant, and
received by the Company at its principal office, accompanied by payment in full
in the manner provided in the Plan. The Participant may purchase less than the
number of Shares covered hereby, provided that no partial exercise of this
option may be for any fractional share.

         (b) CONTINUOUS RELATIONSHIP WITH THE COMPANY REQUIRED. Except as
otherwise provided in this Section 3, this option may not be exercised unless
the Participant, at the time he or she exercises this option, is, and has been
at all times since the Grant Date, an employee, officer or director of, or
consultant or advisor to, the Company or any parent or subsidiary of the Company
as defined in Section 424(e) or (f) of the Code (an "Eligible Participant").

         (c) TERMINATION OF RELATIONSHIP WITH THE COMPANY. If the Participant
ceases to be an Eligible Participant for any reason (except as set forth in this
Section 3), then the right to exercise this option shall terminate three months
after such cessation, or at the end of such longer period as provided in
paragraphs (d), (f), (g) and (h) below, but in no event after the Final Exercise
Date. In this circumstance, this option shall be exercisable only to the extent
that the Participant was entitled to exercise this option on the date of such
cessation.

         (d) TERMINATION BY THE COMPANY FOR JUSTIFIABLE CAUSE OR BY THE
PARTICIPANT FOR GOOD REASON. If the Participant's employment is terminated by
the Company other than for Justifiable Cause (as defined below) or the
Participant voluntarily terminates the Participant's employment with Good Reason
(as defined below), all shares subject to this option that would have vested
within the one-year period following such termination will accelerate,
immediately vest and become exercisable. In such event, the period during which
the Participant may exercise all vested options (including the accelerated
options) shall be extended until one year after the expiration of the Severance
Period (as defined in the agreement between the Participant and the Company
dated June 23, 2005).

         "Justifiable Cause" shall mean the occurrence of any of the following
events: (i) the Participant's conviction of, or plea of NOLO CONTENDERE with
respect to a felony or crime involving moral turpitude, (ii) the Participant's
commission of an act of personal dishonesty or breach of fiduciary duty
involving personal profit in connection with the Company, (iii) the
Participant's commission of an act, or failure to act, which the Board shall
reasonably have found to have involved willful misconduct or gross negligence on
the Participant's part, in the conduct of the Participant's duties as an
employee of the Company, (iv) habitual absenteeism, alcoholism or drug
dependence on the Participant's part which interferes with the performance of
the Participant's duties as an employee of the Company, (v) the Participant's
willful and material failure or refusal to perform the Participant's services as
an employee of the Company, (vi) any material breach by Participant to fulfill
the terms and conditions under which Participant is employed by the Company, or
(vii) the Participant's willful and material failure or refusal to carry out a
direct, lawful written request of the Board.

         "Good Reason" shall mean any action by the Company without the
Participant's prior written consent which results in (i) any requirement by the
Company that Participant perform the Participant's principal duties outside a
radius of 50 miles from the Company's Cambridge, Massachusetts location; (ii)
any material diminution in the Participant's title, position, duties,
responsibilities or authority, including the Participant's ceasing to serve as
the Company's President and Chief Executive Officer or to serve as a member of
the Board; (iii) any breach by the Company of any material provision of the
agreement between the Participant and the Company dated June 23, 2005 and not
cured within thirty (30) days' of written notice thereof; (iv) a reduction in
the Participant's base salary (unless such reduction is effected in connection
with a general and proportionate reduction of salaries for all members of the
Company's management team) or any reduction of the Participant's target bonus
amount to less than 80% of the Participant's annual salary; or (v) any
acquisition, merger or Change of Control involving the Company which results in
the Participant ceasing to serve as the Chief Executive Officer for the
surviving entity and for all direct and indirect parent organizations thereof.

         (e) CHANGE OF CONTROL. In the event of a Change of Control (as defined
in the Plan), and if within one month prior to or twelve months following such
Change of Control, the Participant's employment with the Company or its
successor is terminated other than for Justifiable Cause or terminated by the
Participant for Good Reason, then all outstanding unvested shares under this
option will immediately vest in full.

         (f) EXERCISE PERIOD UPON DISABILITY. If the Participant becomes
disabled (within the meaning of Section 22(e)(3) of the Code) prior to the Final
Exercise Date while he or she is an Eligible Participant, this option shall be
exercisable within the period of one year following the date of disability of
the Participant, but in no event after the Final Exercise Date. In this
circumstance, this option shall be exercisable only to the extent that the
Participant was entitled to exercise this option on the date of his or her
disability. .

         (g) EXERCISE PERIOD UPON DEATH. If the Participant dies prior to the
Final Exercise Date while he or she is an Eligible Participant, this option
shall become immediately exercisable in full and shall be exercisable within the
period of three years following the date of death of the Participant, but in no
event after the Final Exercise Date (it being understood that the option must be
exercised within the period of one year following the date of death in order for
the option to qualify as an incentive stock option). .

         (h) EXERCISE PERIOD UPON RETIREMENT. If the Participant retires prior
to the Final Exercise Date while he or she is an Eligible Participant, and such
Participant has, at the time of such retirement, served as an employee of the
Company for a period of ten years and has, at the time of cessation, reached the
age of fifty-five, then the right to exercise this option shall terminate three
years after such cessation, but in no event after the Final Exercise Date (it
being understood that the option must be exercised within the period of three
months following the date of cessation in order for the option to qualify as an
incentive stock option). In this circumstance, this option shall be exercisable
only to the extent that the Participant was entitled to exercise this option on
the date of such cessation.

4. WITHHOLDING.

         No Shares will be issued pursuant to the exercise of this option unless
and until the Participant pays to the Company, or makes provision satisfactory
to the Company for payment of, any federal, state or local withholding taxes
required by law to be withheld in respect of this option.

5. NONTRANSFERABILITY OF OPTION.

         This option may not be sold, assigned, transferred, pledged or
otherwise encumbered by the Participant, either voluntarily or by operation of
law, except by will or the laws of descent and distribution, and, during the
lifetime of the Participant, this option shall be exercisable only by the
Participant.


6. DISQUALIFYING DISPOSITION.

         If the Participant disposes of Shares acquired upon exercise of this
option within two years from the Grant Date or one year after such Shares were
acquired pursuant to exercise of this option, the Participant shall notify the
Company in writing of such disposition.

7. PROVISIONS OF THE PLAN.

         This option is subject to the provisions of the Plan, a copy of which
is furnished to the Participant with this option.

         IN WITNESS WHEREOF, the Company has caused this option to be executed
under its corporate seal by its duly authorized officer. This option shall take
effect as a sealed instrument.


                                    MILLENNIUM PHARMACEUTICALS, INC.


Dated:   July 18, 2005              By:  /s/ LINDA K. PINE
                                         Linda K. Pine
                                         Senior Vice President, Human Resources



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                         NOTICE OF STOCK OPTION EXERCISE

                               Date: ____________
Millennium Pharmaceuticals, Inc.
40 Landsdowne Street
Cambridge, MA 02139
Attention:  Treasurer

Dear Sir or Madam:

     I am the  holder  of an  Incentive  Stock  Option  granted  to me under the
Millennium  Pharmaceuticals,  Inc. (the  "Company") 2000 Stock Incentive Plan on
__________  for the purchase of _________  shares of Common Stock of the Company
at a purchase price of $__________ per share.

     I hereby exercise my option to purchase  _________  shares of Common Stock,
for which I have enclosed __________ in the amount of ________.  Please register
my stock certificate as follows:

        Name(s):            _______________________
        Address:            _______________________
        Tax I.D. #:         _______________________


Very truly yours,


-----------------------------
(Signature)