Amendment No. 2 to Amended and Restated Collaboration and License Agreement, dated as of July 18, 2016, by and between the Registrant and Pioneer Hi-Bred International, Inc

Certain identified information has been excluded from this exhibit because it is both not material and is the type that the registrant treats as private or confidential. Information that was omitted has been noted in this document with a placeholder identified by the mark “[***]”.

Exhibit 10.9

AMENDMENT #2 to the AMENDED AND RESTATED

COLLABORATION AND LICENSE AGREEMENT

This Amendment #2 to the Amended and Restated Collaboration and License Agreement (“Amendment”), effective July 18, 2016 (the “Amendment #2 Effective Date”), is by and between Pioneer Hi-Bred International, Inc., with headquarters at 7100 NW 62^nd Avenue, PO Box 1014, Johnston, Iowa 50131-1014, USA (“Pioneer”), and Caribou Biosciences, Inc., located at 2929 7^th St., Suite 105, Berkeley, California 94710 (“Caribou Bio”) (Caribou Bio and Pioneer, each individually a “Party”, and together the “Parties”).

WHEREAS, the Parties have signed an Amended and Restated Collaboration and License Agreement dated July 13, 2015 (which as of July 13, 2015, [***] as amended by Amendment #1 to the Amended and Restated Collaboration and License Agreement, dated January 21, 2016. As used in this Amendment, “Agreement” refers to the Amended and Restated Collaboration and License Agreement, as amended; and

WHEREAS, the Parties desire to further amend the Agreement to clarify certain effects of termination of the Agreement;

NOW, THEREFORE, in consideration of the mutual agreements contained in this Amendment, and for good and valuable consideration, the sufficiency of which is hereby acknowledged, the Parties hereto agree as follows:

[***]

IN WITNESS WHEREOF, the Parties have caused this Amendment #2 to the Amended and Restated Collaboration and License Agreement to be executed by their respective authorized representatives.