Cellectis Prices Initial Public Offering of American Depositary Shares

March 24, 2015 – Paris (France) – Cellectis (Alternext: ALCLS – Nasdaq Global Market: CLLS), a pioneering gene-editing company employing proprietary technologies to develop best-in-class products in the emerging field of immuno-oncology, today announced the pricing of its initial public offering of 5,500,000 American Depositary Shares (ADSs), each representing an ordinary share of the Company, at a price to the public of $41.50 per ADS.

The ADSs are expected to begin trading on the Nasdaq Global Market under the ticker symbol “CLLS” on Wednesday, March 25, 2015. In addition, Cellectis has granted the underwriters a 30-day option to purchase up to an additional 825,000 ADSs.

BofA Merrill Lynch, Jefferies and Piper Jaffray & Co. are acting as joint book-running managers for the offering. Oppenheimer & Co. and Trout Capital are acting as co-managers for the offering.

This offering is made only by means of a prospectus. A copy of the final prospectus related to the offering may be obtained at no cost, when available, by visiting EDGAR on the Securities and Exchange Commission's website (www.sec.gov), or from: BofA Merrill Lynch, 222 Broadway, New York, NY 10038, Attn: Prospectus Department, email: dg.prospectus_requests@baml.com or by phone at (866) 500-5408; or Jefferies LLC, Attention: Equity Syndicate Prospectus Department, at 520 Madison Avenue, 12th Floor, New York, NY, 10022, by emailing Prospectus_Department@Jefferies.com or by phone at (877) 547-6340.

A registration statement on Form F-1 relating to these securities has been filed with, and declared effective by, the U.S. Securities and Exchange Commission. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.