SCHEDULE 14A
                      (Rule 14a-101)

         INFORMATION REQUIRED IN PROXY STATEMENT

                 SCHEDULE 14A INFORMATION
   Proxy Statement Pursuant to Section 14(a) of the Securities
           Exchange Act of 1934 (Amendment No. ____)

        Filed by the Registrant                          X
                                                        ---
        Filed by a Party other than the Registrant
                                                        ---
	Check the appropriate box:
        Preliminary Proxy Statement         Confidential, for use
  ---                                   --- of the Commission
                                            Only (as permitted by
                                            Rule 14a-6(e)(2))

        Definitive Proxy Statement
  ---
        Definitive Additional Materials
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        Soliciting Material Pursuant to Rule 14a-12
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                       Diacrin, Inc.
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      (Name of Registrant as Specified In Its Charter)


            -------------------------------------
(Name of Person(s) Filing Proxy Statement if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box):

        No fee required.
  ---
        Fee computed on table below per Exchange Act Rules 14a-6(i)(1)
        and 0-11.

   1. Title of each class of securities to which transaction
applies:
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   2. Aggregate number of securities to which transaction applies:
                                                                   ---
   3. Per unit price or other underlying value of transaction computed
pursuant to Exchange Act Rule 0-11 (set forth the amount on which the
filing fee is calculated and state how it was determined):
                                                            ---
   4. Proposed maximum aggregate value of transaction:
                                                       ---
   5. Total fee paid:
                      ---
     Fee paid previously with preliminary materials:
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     Check box if any part of the fee is offset as provided by
 --- Exchange Act Rule 0-11(a)(2) and identify the filing for which
     the offsetting fee was paid previously. Identify the previous
     filing by registration statement number, or the form or schedule
     and the date of its filing.

     1. Amount previously paid:
                                ---
     2. Form, Schedule or Registration Statement No.:
                                                      ---
     3. Filing Party:
                      ---
     4. Date Filed:
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Soliciting Material Pursuant to Rule 14a-12

     The following information with respect to the proposed
merger of Diacrin, Inc. (the "Company") with and into Genvec,
Inc. was filed as part of the Company's Quarterly Report on Form
10-Q for the period ended March 31, 2003 which was filed with
the Securities and Exchange Commission on May 7, 2003.

     Note 4 of the notes to the Company's unaudited financial
statements for the period ended March 31, 2003 and the overview
section of Item 2. "Management's Discussion and Analysis of
Financial Condition and Results of Operations" contained the
following paragraph:

     "On April 14, 2003, we entered into an Agreement
and Plan of Reorganization and related Agreement and Plan
Merger with GenVec, Inc., a publicly-traded company,
providing for us to merge into GenVec.  Upon
completion of the merger, each outstanding share of our
common stock would be exchanged for 1.5292 shares of
GenVec common stock.  The merger is expected to close in
the third quarter of 2003, subject to the satisfaction of
closing conditions, including receipt of Diacrin and
GenVec stockholder approval."

     In addition, the section of Item 2. "Management's
Discussion and Analysis of Financial Condition and Results of
Operations" entitled "Certain Factors That May Affect Future
Results" contained the following language:

     "Failure to complete the merger with GenVec could
negatively impact the market price of our common stock
and our future business and operations.

     If the merger with GenVec is not completed for any
reason, we will be subject to a number of material risks,
including:

-     under the circumstances described in the merger
agreement, we could be required to pay GenVec a
termination fee in the amount of up to $1.2 million;

-     the market price of our common stock may decline
to the extent that the current market price of such shares
reflects a market assumption that the merger will be
completed;

-     the costs related to the merger, such as legal and
accounting fees and a portion of the investment banking
fees, must be paid even if the merger is not completed; and

-     the benefits that we expect to realize from the
merger would not be realized.

     During the pendency of the merger agreement, we may not
be able to enter into a merger or business combination
with another party at a favorable price because of
restrictions in the merger agreement.   Covenants in the
merger agreement with GenVec also impede our ability to
make acquisitions or complete other transactions that are
not in the ordinary course of business but that could be
favorable to us and our stockholders pending completion
of the merger.  As a result, if the merger is not
consummated, we may be at a disadvantage to our competitors."

Important Additional Information Will Be Filed With The SEC

     GenVec, Inc. plans to file with the SEC a Registration Statement
on Form S-4 in connection with the transaction and GenVec and Diacrin
plan to file with the SEC and mail to their respective stockholders a Joint
Proxy Statement/Prospectus in connection with the transaction. The
Registration Statement and the Joint Proxy Statement/Prospectus will
contain important information about GenVec, Diacrin, the transaction and
related matters.  Investors and security holders are urged to read the
Registration Statement and the Joint Proxy Statement/Prospectus carefully
when they are available.

     Investors and security holders will be able to obtain free copies of
the Registration Statement and the Joint Proxy Statement/Prospectus and
other documents filed with the SEC by GenVec and Diacrin through the
web site maintained by the SEC at www.sec.gov.

     In addition, investors and security holders may obtain free copies
of the documents (when they are available) filed with the SEC by GenVec
by directing a request to: GenVec, Inc., 65 W. Watkins Mill Road,
Gaithersburg, MD 20878, Attn: Corporate Secretary.  Investors and
security holders may obtain free copies of the documents filed with the
SEC by Diacrin by contacting Diacrin, Inc. at Building 96 13th Street,
Charlestown, MA 02129.

     GenVec, Diacrin and their respective executive officers and
directors may be deemed to be participants in the solicitation of proxies
from the stockholders of GenVec and Diacrin in favor of the acquisition.
Information about the executive officers and directors of GenVec and their
ownership of GenVec common stock is set forth in the proxy statement for
GenVec's 2002 Annual Meeting of Shareholders, which was filed with the
SEC on April 29, 2002.  Information about the executive officers and
directors of Diacrin and their ownership of Diacrin common stock is set
forth in the proxy statement for Diacrin's 2002 Annual Meeting of
Shareholders, which was filed with the SEC on July 25, 2002.  Certain
directors and executive officers of GenVec and Diacrin may have direct or
indirect interests in the merger due to securities holdings, pre-existing or
future indemnification arrangements, vesting of options, and rights to
severance payments if their employment is terminated following the
merger. Shareholders of GenVec and Diacrin holding approximately 17%
and 35% of the respective company's shares have agreed to vote their
shares in favor of the acquisition.

     Additional information regarding GenVec, Diacrin, and the
interests of their respective executive officers and directors in the
acquisition will be contained in the joint proxy statement/prospectus
regarding the acquisition.

     Investors and security holders are urged to read the joint proxy
statement/prospectus and the other relevant materials when they become
available before making any voting or investment decisions with respect to
the acquisition.

Forward-Looking Statements

     This press release contains forward-looking statements, including
information regarding our merger with GenVec. There are a number of
important factors that could cause actual events or operating results to
differ materially from those indicated by such forward-looking statements,
such as our ability to complete the merger with GenVec. For a more detailed
discussion of these and other factors, see the Company's Quarterly Report on
Form 10-Q for the quarter ended March 31, 2003 as filed with the Securities
and Exchange Commission.