SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                 SCHEDULE 13G
                                (Rule 13d-102)


             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13d-2(b)

                                (Amendment No. 2)


                                 Cerus Corporation
--------------------------------------------------------------------------------
                                (Name of Issuer)


                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                   157085101
--------------------------------------------------------------------------------
                                 (CUSIP Number)


                                 December 31, 2003
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)


     Check the  appropriate  box to  designate  the rule  pursuant to which this
Schedule is filed:

          [_]  Rule 13d-1(b)

          [X]  Rule 13d-1(c)

          [_]  Rule 13d-1(d)


----------
(1)  The  remainder  of this  cover  page  shall be filled  out for a  reporting
     person's  initial  filing on this form with respect to the subject class of
     securities,  and for any subsequent amendment containing  information which
     would alter the disclosures provided in a prior cover page.

     The  information  required in the remainder of this cover page shall not be
deemed to be "filed"  for the purpose of Section 18 of the  Securities  Exchange
Act of 1934 or otherwise  subject to the  liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield Capital, L.P.

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     1,122,000

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     1,122,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,122,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [-]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     5.09%

12.  TYPE OF REPORTING PERSON*

     PN




CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield Partners, L.P.

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     New York

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     1,122,000

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     1,122,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,122,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [-]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     5.09%

12.  TYPE OF REPORTING PERSON*

     PN




CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield Management Company, L.P.

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     New York

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     1,078,000

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     1,078,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,078,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [-]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     4.89%

12.  TYPE OF REPORTING PERSON*

     PN




CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield International Limited

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     British Virgin Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     1,078,000

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     1,078,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,078,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [-]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     4.89%

12.  TYPE OF REPORTING PERSON*

     CO




CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Arnold H. Snider

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     2,200,000

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     2,200,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,200,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [-]
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     9.97%

12.  TYPE OF REPORTING PERSON*

     IN




CUSIP No.   157085101
            ---------------------


Item 1(a).  Name of Issuer:


            Cerus Corporation
            --------------------------------------------------------------------

Item 1(b).  Address of Issuer's Principal Executive Offices:


            2411 Stanwell Drive
            Concord, California 94520

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


Item 2(a).  Name of Person Filing:


            Arnold H. Snider, Deerfield Capital, L.P., Deerfield Management
            Company, L.P., Deerfield International Limited
            --------------------------------------------------------------------

Item 2(b).  Address of Principal Business Office, or if None, Residence:


            Arnold H. Snider, Deerfield Capital, L.P., Deerfield Management
            Company, L.P., 780 Third Avenue, 37th Floor, New York, NY 10017

            Deerfield International Limited, c/o Hemisphere Management (B.V.I.)
            Limited, Bison Court, Columbus Centre, P.O. Box 3460, Road Town,
            Tortola, British Virgin Islands
            --------------------------------------------------------------------

Item 2(c).  Citizenship:

            Mr. Snider - United States citizen

            Deerfield Capital, L.P. and Deerfield Partners,
            L.P. - Delaware limited partnerships

            Deerfield Management Company, L.P. - New York limited
            partnership

            Deerfield International Limited - British Virgin
            Islands corporation


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

Item 2(d).  Title of Class of Securities:


            Common Stock
            --------------------------------------------------------------------

Item 2(e).  CUSIP Number:


            157085101
            --------------------------------------------------------------------


Item 3.     If This Statement  is Filed  Pursuant to  Rule 13d-1(b), or 13d-2(b)
            or (c), Check Whether the Person Filing is a:

     (a)  [_]  Broker or dealer registered under Section 15 of the Exchange Act.

     (b)  [_]  Bank as defined in Section 3(a)(6) of the Exchange Act.

     (c)  [_]  Insurance  company as defined in Section 3(a)(19) of the Exchange
               Act.

     (d)  [_]  Investment  company  registered under Section 8 of the Investment
               Company Act.

     (e)  [_]  An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

     (f)  [_]  An employee  benefit plan or endowment  fund in  accordance  with
               Rule 13d-1(b)(1)(ii)(F);

     (g)  [_]  A parent  holding  company or control  person in accordance  with
               Rule 13d-1(b)(1)(ii)(G);

     (h)  [_]  A savings  association  as defined in Section 3(b) of the Federal
               Deposit Insurance Act;

     (i)  [_]  A  church  plan  that  is  excluded  from  the  definition  of an
               investment  company  under  Section  3(c)(14)  of the  Investment
               Company Act;

     (j)  [_]  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

Item 4.  Ownership.

     Provide  the  following  information  regarding  the  aggregate  number and
percentage of the class of securities of the issuer identified in Item 1.

     (a)  Amount beneficially owned:

          Deerfield  Capital,  L.P.  and  Deerfield  Partners,  L.P. - 1,122,000
          shares; Deerfield Management Company, L.P. and Deerfield International
          Limited -  1,078,000  shares;  Arnold H.  Snider -  2,200,000  shares.
          ----------------------------------------------------------------------

     (b)  Percent of class:

          Deerfield  Capital,  L.P. and Deerfield  Partners,  L.P. - 5.09%;
          Deerfield  Management Company,  L.P. and Deerfield  International
          Limited    -    4.89%;     Arnold     H.     Snider    -    9.97%
          ----------------------------------------------------------------------

     (c)  Number of shares as to which such person has:

          (i)   Sole power to vote or to direct the vote          0
                                                        -----------------------,


          (ii)  Shared power to vote or to direct the vote    Deerfield Capital,
                                                              L.P. and Deerfield
                                                              Partners, L.P. -
                                                              1,122,000;
                                                              Deerfield
                                                              Management
                                                              Company, L.P.
                                                              and Deerfield
                                                              International
                                                              Limited -
                                                              1,078,000;
                                                              Arnold H. Snider -
                                                              2,200,000.
                                                          ---------------------,


          (iii) Sole power to dispose or to direct the            0
                disposition of                            _____________________,


          (iv)  Shared power to dispose or to direct the
                disposition of
                                                             Deerfield Capital,
                                                             L.P. and Deerfield
                                                             Partners, L.P. -
                                                             1,122,000;
                                                             Deerfield
                                                             Management Company,
                                                             L.P. and Deerfield
                                                             International
                                                             Limited  -
                                                             1,078,000;
                                                             Arnold H.
                                                             Snider -
                                                             2,220,000.
                                                         ---------------------.

     The Reporting Persons  specifically  disclaim  beneficial  ownership in the
securities  reported  herein  except to the extent of their  pecuniary  interest
therein.

Item 5.  Ownership of Five Percent or Less of a Class.

     If this  statement  is being  filed to report  the fact that as of the date
hereof the reporting  person has ceased to be the beneficial  owner of more than
five percent of the class of securities check the following [ ].

         N/A
         -----------------------------------------------------------------------


Item 6.  Ownership of More Than Five Percent on Behalf of Another Person.

     If any other  person is known to have the right to  receive or the power to
direct the receipt of dividends  from,  or the  proceeds  from the sale of, such
securities,  a statement  to that effect  should be included in response to this
item and, if such interest relates to more than five percent of the class,  such
person  should be  identified.  A listing of the  shareholders  of an investment
company registered under the Investment Company Act of 1940 or the beneficiaries
of employee benefit plan, pension fund or endowment fund is not required.

         N/A
         -----------------------------------------------------------------------


Item 7.  Identification and  Classification of the Subsidiary Which Acquired the
         Security  Being  Reported on by the Parent  Holding  Company or Control
         Person.

     If a parent  holding  company  or Control  person has filed this  schedule,
pursuant to Rule  13d-1(b)(1)(ii)(G),  so indicate under Item 3(g) and attach an
exhibit  stating the  identity  and the Item 3  classification  of the  relevant
subsidiary.  If a parent  holding  company  or  control  person  has filed  this
schedule  pursuant to Rule 13d-1(c) or Rule 13d-1(d),  attach an exhibit stating
the identification of the relevant subsidiary.

         N/A
         -----------------------------------------------------------------------


Item 8.  Identification  and  Classification  of Members of the Group.

     If a group has filed this schedule  pursuant to  ss.240.13d-1(b)(1)(ii)(J),
so indicate under Item 3(j) and attach an exhibit  stating the identity and Item
3 classification of each member of the group. If a group has filed this schedule
pursuant to  ss.240.13d-1(c) or  ss.240.13d-1(d),  attach an exhibit stating the
identity of each member of the group.

         N/A
         -----------------------------------------------------------------------


Item 9.  Notice of Dissolution of Group.

     Notice of dissolution of a group may be furnished as an exhibit stating the
date  of  the   dissolution  and  that  all  further  filings  with  respect  to
transactions in the security reported on will be filed, if required,  by members
of the group, in their individual capacity. See Item 5.

          N/A
          ----------------------------------------------------------------------

Item 10.  Certifications.

          "By signing  below I certify  that,  to the best of my  knowledge  and
          belief, the securities referred to above were not acquired and are not
          held for the purpose of or with the effect of changing or  influencing
          the control of the issuer of the  securities and were not acquired and
          are not held in connection with or as a participant in any transaction
          having such purpose or effect."


                                    SIGNATURE

     After  reasonable  inquiry and to the best of my  knowledge  and belief,  I
certify that the information  set forth in this statement is true,  complete and
correct.

DEERFIELD CAPITAL, L.P.

By:  Snider Capital Corporation,
     General Partner

By:  /s/ Arnold H. Snider
         ---------------------------
         Arnold H. Snider, President

DEERFIELD PARTNERS, L.P.

By:  Deerfield Capital, L.P.

By:  Snider Capital Corporation,
     General Partner

By: /s/ Arnold H. Snider
        ---------------------------
        Arnold H. Snider, President

DEERFIELD MANAGEMENT COMPANY, L.P.

By:  Snider Management Corporation,
     General Partner

By:  /s/ Arnold H. Snider
         --------------------------
         Arnold H. Snider, President

DEERFIELD INTERNATIONAL LIMITED

By:  Deerfield Management Company, L.P.

By:  Snider Management Corporation,
     General Partner

By:  /s/ Arnold H. Snider
         --------------------------
         Arnold H. Snider, President

ARNOLD H. SNIDER

     /s/ Arnold H. Snider
         -------------------------


Date:  February 11, 2004




                                    Exhibit A

                                    Agreement

     The  undersigned  agree that this  Schedule  13G dated  February  11,  2004
relating to the Common  Stock of Cerus  Corporation  shall be filed on behalf of
the undersigned.



DEERFIELD CAPITAL, L.P.

By:     Snider Capital Corporation,
        General Partner

By:     /s/ Arnold H. Snider
            ---------------------------
            Arnold H. Snider, President

DEERFIELD PARTNERS, L.P.

By:     Deerfield Capital, L.P.

By:     Snider Capital Corporation,
        General Partner

By:     /s/ Arnold H. Snider
            ---------------------------
            Arnold H. Snider, President

DEERFIELD MANAGEMENT COMPANY, L.P.

By:     Snider Management Corporation,
        General Partner

By:     /s/ Arnold H. Snider
            -----------------------
            Arnold H. Snider, President

DEERFIELD INTERNATIONAL LIMITED

By:     Deerfield Management Company, L.P.

By:     Snider Management Corporation,
        General Partner

By:     /s/ Arnold H. Snider
            -----------------------
            Arnold H. Snider, President

ARNOLD H. SNIDER

        /s/ Arnold H. Snider

00871.0001 #462755