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Exhibit 10.18

Millennium Pharmaceuticals, Inc.
Description of Non-Employee Director Compensation

        We do not pay directors who are also Millennium employees any additional
compensation for their service as a director. We do pay our non-employee
directors for their service as directors.

        Each year, the Board Governance Committee reviews the compensation we
pay to our non-employee directors. The Committee compares our Board compensation
to compensation paid to non-employee directors by similarly sized public
companies in similar businesses. The Committee also considers the
responsibilities that we ask our Board members to assume and the amount of time
required to perform those responsibilities.

        Below we show the rate of compensation that we pay to our non-employee
directors effective January 1, 2005.

Cash Compensation

        Each director who is not an employee of Millennium receives:

Type of Fee

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  Amount

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  For each

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Annual retainer:   $ 25,000   Year of service
Additional annual retainer for lead outside director:
 
$
10,000
 
Year of service
Attendance:
 
$
2,000
 
Board meeting attended in person
 
 
$
1,000
 
Board meeting attended by conference telephone
 
 
$
1,000
 
Board committee meeting attended in person
 
 
$
750
 
Board committee meeting attended by conference telephone

        Millennium also reimburses non-employee directors for reasonable travel
and out-of-pocket expenses incurred in connection with their service as
directors.

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Stock Compensation

        Directors also participate in our 2000 Stock Incentive Plan. Under the
option program for directors adopted by the Board, our non-employee directors
receive stock option grants as follows:

 
  Number
of shares

--------------------------------------------------------------------------------

  Granted in three
installments on

--------------------------------------------------------------------------------

  Vesting
Schedule

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Initial Option Grant:   35,000   the date the director is first elected, one
month later and two months later   vest on a monthly basis beginning one month
from the date of election and become fully vested on the fourth anniversary of
the date of election
Annual Option Grant:
 
15,000
 
May 1st, June 1st and July 1st of each year, prorated for service on the Board
of less than one year
 
vest on a monthly basis beginning as of June 1st in the year granted and become
fully vested on May 1st of the fourth year after the grant date
Committee Chair:
 
500
 
the dates of the annual option grant
 
same as annual grant
Lead Outside Director:
 
5,000
 
the dates of the annual option grant
 
same as annual grant

        Each option terminates on the earlier of ten years after the date of
grant or the date 90 days after the option holder ceases to serve as a director
or employee (or one year in the case of disability and three years in the event
of death).

        Under the 2000 Plan, an option becomes fully vested in the event of the
death of the director. The exercise price of options granted under the 2000 Plan
is equal to the closing price of Millennium common stock as quoted on the NASDAQ
stock market on the date of grant.

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Exhibit 10.18