BACKGROUND

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                                                                   EXHIBIT 10.11

                            NINTH AMENDMENT TO LEASE

                THIS NINTH AMENDMENT TO LEASE (this "AMENDMENT") is made and
entered into as of July 31, 2000, by and between MISSION VACAVILLE LIMITED
PARTNERSHIP, a California limited partnership ("LANDLORD"), and LARGE SCALE
BIOLOGY CORPORATION, a California corporation (formerly Biosource Technologies,
Inc.) ("TENANT"), with reference to the following Recitals:

                                   BACKGROUND

                A. Landlord and Tenant are currently parties to the Xxxx Valley
Business Park Office Lease dated as of October 15, 1987, as amended by the First
Amendment thereto dated as of July 1, 1989, the Second Amendment thereto dated
as of January 1, 1992, the Third Amendment thereto dated as of June 30, 1992,
the Fourth Amendment thereto dated as of November 22, 1995, the Fifth Amendment
thereto dated as of November 22, 1996 (the "Fifth Amendment"), the Sixth
Amendment thereto dated as of September 8, 1997, the Seventh Amendment thereto
dated as of July 25, 1998 and the Eighth Amendment thereto dated as of May 19,
1999 (as amended, the "Lease"), pursuant to which Tenant currently leases
certain office space within the Interchange Business Park -Vacaville
("Building"), at 0000 Xxxx Xxxxxx Xxxxxxx, Xxxxxxxxx, Xxxxxxxxxx 00000, which
space is more particularly described in the Lease (the "Premises").

                B. Landlord and Tenant desire to confirm Tenant's extension of
the Term of the Lease and the Base Rent applicable to the Extension Term.

                NOW, THEREFORE, in consideration of the foregoing Recitals, the
agreements set forth herein, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, Landlord and Tenant
hereby agree as follows:

        1. Definitions. All initially capitalized terms not otherwise defined
herein shall have the meanings set forth in the Lease. From and after the date
hereof, references to the Lease shall mean the Lease as amended hereby. In the
event of any inconsistency between the terms of the Lease as amended to date and
the terms of this Amendment, the terms of this Amendment shall prevail.

        2. Extension Term. In accordance with Section 3 of the Fifth Amendment,
Tenant has exercised its option to the Term of the Lease for a period of three
(3) years, commencing on January 1, 2001 and ending on December 31, 2003. The
initial Base Rent for the Extension Term is $44,912.50 per month. Starting
January 1,2002, the Base Rent shall be multiplied by the quotient of (A) the
CPI-U published most recently prior to such date divided by (B) the CPI- U
published most recently as of January 1,2001, provided that the increase shall
not be less than four percent (4%) and shall not be more than eight percent
(8%). On January 1,2003, the Base Rent shall be multiplied by the quotient of
(A) the CPI-U published most recently prior to such date divided by (B) the
CPI-U published most recently as of January 1,2002, provided that the increase
shall not be less than four percent (4%) and shall not be more than eight
percent (8%). Section 3(e) of the Fifth Amendment is deleted in its entirety.



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        3. RATIFICATION. The Lease, as amended by this Amendment, is hereby
ratified and confirmed in all respects and remains in full force and effect.
This amendment shall be effective as of the date hereof upon execution and
delivery by both Landlord and Tenant. Except for those provisions of the Lease
which are expressly amended hereby, the Lease remains unmodified and unchanged.

        4. COUNTERPARTS. This Amendment may be executed in counterparts, each of
which shall be an original, but all of which together shall constitute one
agreement.

        IN WITNESS WHEREOF, Tenant and Landlord have: executed this Amendment as
of the date first above written.

                "LANDLORD"

                MISSION VACAVILLE LIMITED PARTNERSHIP,
                a California limited partnership

                By:    Mission Airport Park Development Company,
                       a California corporation
                       Its General Partner


                       By:    /s/ XXXXXX X. XXXXXXXXX
                       Name:  Xxxxxx X. Xxxxxxxxx
                       Its:   Chief Financial Officer

                "TENANT"

                LARGE SCALE BIOLOGY CORPORATION,
                a California corporation


                By:    /s/ XXXXX X. XXXXX
                Name:  Xxxxx X. XxXxx
                Its:   Senior Vice President