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SEC 1473    POTENTIAL PERSONS WHO ARE TO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED IN THIS FORM ARE NOT REQUIRED TO
(09-02)     RESPOND UNLESS THE FORM DISPLAYS A CURRENTLY VALID OMB CONTROL NUMBER.
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--------                                       UNITED STATES SECURITIES AND EXCHANGE COMMISSION        -----------------------------
 FORM 3                                                WASHINGTON, D.C. 20549                                   OMB APPROVAL
--------                                                                                               -----------------------------
                                       INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES          OMB Number:       3235-0104
                                                                                                        Expires:   January 31, 2005
                              FILED PURSUANT TO SECTION 16(a) OF THE SECURITIES EXCHANGE ACT OF 1934,   Estimated average burden
                                 SECTION 17(a) OF THE PUBLIC UTILITY HOLDING COMPANY ACT OF 1935 OR     hours per response .... 0.5
(Print or Type Responses)                SECTION 30(h) OF THE INVESTMENT COMPANY ACT OF 1940           -----------------------------
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1. Name and Address of Reporting Person*         2. Date of Event Re-   4. Issuer Name AND Ticker or Trading Symbol
                                                    quiring Statement
    Zenner           Patrick           J.           (Month/Day/Year)       EXACT Sciences Corporation (EXAS)
-------------------------------------------------                       ------------------------------------------------------------
    (Last)          (First)          (Middle)          03/21/03         5. Relationship of Reporting Person(s) 6. If Amendment, Date
                                                 -----------------------    to Issuer (Check all applicable)      of Original
                                                 3. I.R.S. Identifi-     X  Director           10% Owner         (Month/Day/Year)
 C/O EXACT Sciences Corporation                     cation Number of    ----               ----
 63 Great Road                                      Reporting Person,        Officer (give      Other (specify  --------------------
-------------------------------------------------   if an entity             title below)       below)         7. Individual or
                    (Street)                        (voluntary)         ----               ----                   Joint/Group Filing
                                                                                                                  (Check Applicable
                                                                                                                   Line)
                                                                           ---------------------------         _X_Form filed by One
    Maynard           MA                01754                                                                     Reporting Person
-------------------------------------------------
    (City)          (State)            (Zip)                                                                   ___Form filed by
                                                                                                                  More than One
                                                                                                                  Reporting Person

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                                            TABLE I -- NON-DERIVATIVE SECURITIES BENEFICIALLY OWNED

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1. Title of Security                              2. Amount of Securities       3. Ownership        4. Nature of Indirect Beneficial
   (Instr. 4)                                        Beneficially Owned            Form: Direct        Ownership (Instr. 5)
                                                     (Instr. 4)                    (D) or Indirect
                                                                                   (I)  (Instr. 5)
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                     TABLE II - DERIVATIVE SECURITIES BENEFICIALLY OWNED (E.G., PUTS, CALLS, WARRANTS, OPTIONS, CONVERTIBLE
                                SECURITIES)
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1. Title of Derivative Security    2. Date Exer-  3. Title and Amount of Securities   4. Conver-   5. Owner-   6. Nature of Indirect
   (Instr. 4)                         cisable and    Underlying Derivative Security      sion or      ship        Beneficial
                                      Expiration     (Instr. 4)                          Exercise     Form of     Ownership
                                      Date                                               Price of     Deriv-      (Instr. 5)
                                     (Month/Day/                                         Deri-        ative
                                      Year)                                              vative       Security:
                                   --------------------------------------------------    Security     Direct
                                                                             Amount                   (D) or
                                    Date     Expir-                          or                       Indirect
                                    Exer-    ation           Title           Number                   (I)
                                    cisable  Date                            of
                                                                             Shares                 (Instr. 5)
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Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

Explanation of Responses:

                                   ***                             3/24/03
                    -------------------------------------  ----------------------
                       **Signature of Reporting Person             Date

                         *** By: /s/ Stephen A. Read
                                 Attorney-in-Fact

 *If the form is filed by more than one reporting person, SEE instruction 5(b)(v).

**Intentional misstatements or omissions of facts constitute Federal
  Criminal Violations.  SEE 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient,
      SEE Instruction 6 for procedure.






                                POWER OF ATTORNEY

       KNOW ALL MEN BY THESE PRESENTS, that the person whose signature appears
below hereby revokes all powers of attorney previously given and constitutes and
appoints Don M. Hardison, John A. McCarthy, Jr. and Stephen Read, and any one of
them acting singly, the true and lawful attorneys-in-fact and agents, with full
power of substitution and resubstitution, for the undersigned and in the
undersigned's name, place and stead, in any and all capacities (until revoked in
writing) to sign any and all instruments, certificates and documents required to
be executed on behalf of the undersigned as an individual or on behalf of the
undersigned's holding company, as the case may be, pursuant to sections 13 and
16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and
any and all regulations promulgated thereunder, and to file the same, with all
exhibits thereto, and any other documents in connection therewith, with the
Securities and Exchange Commission, and with any other entity when and if such
is mandated by the Exchange Act or by the By-laws of the National Association of
Securities Dealers, granting unto said attorneys-in-fact and agents full power
and authority to do and perform each and every act and thing requisite and
necessary fully to all intents and purposes as the undersigned might or could do
in person thereby ratifying and confirming all that said attorneys-in-fact and
agents, or their substitute or substitutes, may lawfully do or cause to be done
by virtue hereof.

       IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 23rd
day of March 2003.


                                         /s/ PATRICK J. ZENNER
                                         ------------------------------------
                                         Patrick J. Zenner