EX-10.13





 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 10.13 
 AMENDMENT
#6 to the 
 AMENDED AND RESTATED 

COLLABORATION AND LICENSE AGREEMENT 

This Amendment #6 to the Amended and Restated Collaboration and License Agreement (“Amendment #5”), effective June 2, 2019 (the
“Amendment #6 Effective Date”), is by and between Pioneer Hi-Bred International, Inc., with headquarters at 7100 NW 62” Avenue, PO Box 1014, Johnston, Iowa 50131-1014, USA (“Pioneer”),
and Caribou Biosciences, Inc., located at 2929 7th St., Suite 105, Berkeley, California 94710 (“Caribou Bio”) (Caribou Bio and Pioneer, each individually a “Party,” and together the “Parties”). 

WHEREAS, the Parties have a 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; Amendment #2 to the Amended and Restated Collaboration and License Agreement, dated July 18,
2016; Amendment #3 to the Amended and Restated Collaboration and License Agreement, dated March 13, 2017; Amendment #4 to the Amended and Restated Collaboration and License Agreement, dated June 26, 2017; and Amendment #5, dated
May 26, 2018 (collectively, the “Agreement”); and 
 WHEREAS, the Parties desire to further amend the Agreement in light of
certain corporate changes relating to Pioneer; 
 NOW, THEREFORE, in consideration of the mutual agreements contained in this Amendment #5,
and for good and valuable consideration, the sufficiency of which is hereby acknowledged, the Parties hereto agree as follows: 
  

	 	1.	 All capitalized terms not defined in this Amendment #6 shall have the meanings set forth in the Agreement.



  

	 	2.	 At the end of Section 6.3(a)(iv) of the Agreement, the following is added to the end of the section:



  

	 	[***]	 


  

	 	[***]	 


  

	 	4.	 Nothing in this Amendment #6 is intended to modify or restrict any rights or obligations in the Agreement to
any other intellectual property, including Program IP, as defined in Section 1.43 of the Agreement, nor the licenses granted by each Party to the other Party under such Program IP, as set forth in the Agreement. 



 

	 	5.	 Except as explicitly set forth in this Amendment #6, no other terms of the Agreement are amended and all other
such terms of the Agreement shall remain in full force and effect. 


  

	 	6.	 This Amendment #6 may be executed in any number of counterparts, including facsimile or scanned PDF documents.
Each such counterpart, facsimile or scanned PDF document shall be deemed an original instrument, and all of which, together, shall constitute one and the same executed Agreement. 














 IN WITNESS WHEREOF, the Parties have caused this Amendment #6 to the Amended and Restated
Collaboration and License Agreement to be executed by their respective authorized representatives. 
  

							
	Pioneer Hi-Bred International, Inc.	 	Caribou Biosciences, Inc.


							
				
	By:	 	         /s/ Mathias L. Müller
	 	By:	 	         /s/ Rachel E.
Haurwitz



							
		 	Name:         Mathias L. Müller	 		 	Name:         Rachel E. Haurwitz
		 	Title:         Director, Business Development	 		 	Title:         President and CEO
				
		 	Date:         June 26, 2019	 		 	Date:         June 28, 2019


  
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