BERKELEY, CA – May 16, 2016 – Caribou Biosciences, Inc., a developer of CRISPR-Cas technologies for genome engineering, today announced the completion of a $30 million Series B financing round. The financing included the participation of new investors Anterra Capital, Heritage Group, Maverick Capital Ventures, and Pontifax AgTech. Also participating in the round were existing investors, including F-Prime Capital Partners, Novartis, Mission Bay Capital, and 5 Prime Ventures."We are delighted to have the support of such an esteemed group of new and current investors, and view the caliber of the participants as further validation of the potential of our CRISPR-Cas genome engineering platform to transform the development of new medical therapies and bio-based products," said Rachel Haurwitz, Ph.D., President and Chief Executive Officer and co-founder of Caribou. "The proceeds from this financing will enable us to continue to expand our industry-leading CRISPR gene editing technology platform and accelerate our efforts in highly promising application areas in agriculture, therapeutics, biological research, and industrial biotechnology. We look forward to working with this outstanding group of investors, and bringing their deep expertise and guidance to bear as we deliver on the promise of our technology platform."Caribou also announced today that Philip Austin, Founding Partner at Anterra Capital, has joined the company's Board of Directors, representing the Series B investor class."Caribou’s CRISPR-Cas platform offers unparalleled precision and speed of genome engineering. This technology is already leading to novel ways of treating previously incurable human diseases. We see the same transformative potential in agriculture," remarked Mr. Austin. "Anterra was established to help transform the food sector by bringing cutting edge technologies into this industry. We are excited to be working with the Caribou management team as they seek to expand the commercial applications of their genome editing platform across therapeutics, agriculture, and other industries."Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. represented Caribou in the transaction.

About Caribou Biosciences

Caribou is a developer of cellular engineering and analysis solutions based on CRISPR technologies. The company was founded by pioneers of CRISPR-Cas biology based on research carried out in the Doudna Laboratory at the University of California, Berkeley. Caribou's tools and technologies provide transformative capabilities to therapeutic development, agricultural biotechnology, industrial biotechnology, and basic and applied biological research. For more information, visitwww.cariboubio.com and follow the company @CaribouBio. "Caribou Biosciences" and the Caribou logo are trademarks of Caribou Biosciences, Inc.

Media Contact:

Jessi ColundFeinstein Kean Healthcarejessi.colund@fkhealth.com952-649-8600

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licensing@cariboubio.com