Calyxt Announces Full Exercise of Over-Allotment Option and Closing of its Initial Public Offering ST. PAUL, Minn. & NEW YORK--(BUSINESS WIRE)

Announces Full Exercise of Over-Allotment Option and Closing of its

Initial Public Offering

ST. PAUL, Minn. & NEW YORK--(BUSINESS WIRE)--July 25, 2017--Cellectis

S.A. (NASDAQ:CLLS) and Calyxt, Inc. (NASDAQ:CLXT) announced today the

closing of Calyxt's initial public offering of 8,050,000 shares of its

common stock at the initial public offering price of $8.00 per share

(the "Offering"). The number of shares issued in the Offering includes

the exercise in full of the underwriters' option to purchase up to

1,050,000 additional shares. Calyxt received approximately $64.4 million

in proceeds from the offering, before deducting underwriting fees and

estimated offering expenses. Calyxt's shares of common stock are traded

on the NASDAQ Global Market under the symbol "CLXT".

Calyxt is Cellectis' gene editing agriculture company. Cellectis owns

approximately 79.9% of Calyxt's outstanding shares of common stock.

Citigroup, Jefferies and Wells Fargo Securities acted as joint

book-running managers for the proposed offering. BMO Capital Markets and

Ladenburg Thalmann acted as co-managers.

A registration statement on Form S-1 relating to these securities was

declared effective by the U.S. Securities and Exchange Commission. A

copy of the final prospectus relating to this Offering may be obtained

from Citigroup Global Markets Inc., c/o Broadridge Financial Solutions,

1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at (800)

831-9146, Jefferies LLC, Attention: Equity Syndicate Prospectus

Department, 520 Madison Avenue, 2nd Floor, New York, NY 10022, or by

telephone at (877) 547-6340, or by e-mail at Prospectus_Department@Jefferies.com,

or Wells Fargo Securities, Attention: Equity Syndicate Department, 375

Park Avenue, New York, New York, 10152, at (800) 326-5897 or by email at cmclientsupport@wellsfargo.com.

The final prospectus is also available at www.sec.gov. This press

release shall not constitute an offer to sell or the solicitation of an

offer to buy these securities, nor shall there be any sale of these

securities in any state or jurisdiction in which such offer,

solicitation or sale would be unlawful prior to registration or

qualification under the securities laws of any such state or

This press release contains inside information within the meaning of

Article 7(1) of the EU Market Abuse Regulation.

Jennifer Moore, 917-580-1088

media@calyxt.com / media@cellectis.com

Strategic Communications

Caitlin Kasunich, 212-896-1241

Simon Harnest, 646-385-9008

VP Corporate Strategy