Cellectis

AGM Information • May 20, 2016

PRESS RELEASE

Cellectis S.A. Reports Results from Shareholders' General Meeting Held on May 17, 2016

New York, May 19, 2016 – Cellectis S.A. Shareholders' General Meeting (Alternext: ALCLS - Nasdaq: CLLS) was held on Tuesday, May 17, 2016 in Paris, at its head office.

At the meeting, during which more than 62% of voting rights were exercised, 21 of 22 resolutions were adopted.

Each of the 21 resolutions, adopted in accordance with the recommendation of the board of directors, received more than 75% votes in favor. Resolution No. 22, regarding a capital increase reserved for members of a company savings plan, was rejected in accordance with the recommendation of the board of directors.

The resolutions adopted by Cellectis' shareholders included:

• The approval of the financial statements for the financial year ended December 31, 2015
• The approval of specified related-party agreements
• The reappointment of Mr. Mathieu Simon to the board of directors
• Authorization of a share repurchase plan and authorization of the retirement of the shares acquired through it
• Delegations of authority given to the board of directors to increase share capital up to specified limits
• Resolutions authorizing Cellectis to grant its executive officers, employees, consultants and directors equity compensation up to specified limits

The full results of the vote can be examined on the company's website (www.cellectis.com).

About Cellectis

Cellectis is a biopharmaceutical company focused on developing immunotherapies based on gene edited CAR T-cells (UCART). The company's mission is to develop a new generation of cancer therapies based on engineered T-cells. Cellectis capitalizes on its 16 years of expertise in genome engineering - based on its flagship TALEN® products and meganucleases and pioneering electroporation PulseAgile technology - to create a new generation of immunotherapies. CAR technologies are designed to target surface antigens expressed on cells. Using its life-sciencefocused, pioneering genome-engineering technologies, Cellectis' goal is to create innovative products in multiple fields and with various target markets. Cellectis is listed on the Nasdaq market (ticker: CLLS) and on the NYSE Alternext market (ticker: ALCLS). To find out more about us, visit our website: www.cellectis.com

Talking about gene editing? We do it.

TALEN® is a registered trademark owned by the Cellectis Group.

For further information, please contact:

Media contacts Jennifer Moore, VP Communications Phone: +1 917-580-1088 email: media@cellectis.com

Caitlin Kasunich, KCSA Strategic Communications Phone: +1 212.896.1241 email: ckasunich@kcsa.com

Investor relations contact Simon Harnest, VP Corporate Strategy and Finance Phone: +1 646-385-9008 email: simon.harnest@cellectis.com

Disclaimer

This press release and the information contained herein do not constitute an offer to sell or subscribe, or a solicitation of an offer to buy or subscribe, for shares in Cellectis in any country. This press release contains forward-looking statements that relate to the Company's objectives based on the current expectations and assumptions of the Company's management only and involve risk and uncertainties that could cause the Company to fail to achieve the objectives expressed by the forward-looking statements above.