Press Release

Cellectis S.A. announces participation in the MidCap Event.

Biocitech, France - September the 11^th, 2007 - Cellectis S.A. (Alternext: ALCLS), the rational genome engineering company developing a new range of custom DNA rewriting products for the research, healthcare and industrial sectors, today announced that it will participate in the MidCap Event, a forum dedicated to meetings between institutional investors and listed companies from the Euronext Zone, on Monday 17^th and Tuesday 18^th of September in Paris, 'Palais Brongniart', Place de la Bourse (hosted by Invest Securities).

During these two days, André Choulika, founder and CEO, and Marc le Bozec, CFO, will present Cellectis to institutional investors.

The upcoming conferences Cellectis will attend:

• Bio Investor Forum, October 9^th to 11^th, San Francisco, CA, USA
• Rodman & Renshaw's 9^th annual healthcare conference, November 6^th and 7^th , NY (USA)
• Natixis Securities MidCap healthcare conference, November 16^th, Paris
• Actionaria, November 16^th and 17^th, Paris.

About Cellectis S.A.

Cellectis SA (www.cellectis.com) is a world-leading company in genome engineering and genome surgery. It focuses on developing new tools for rational reverse genetics and targeted recombination. In particular, Cellectis designs meganucleases (small proteins) that cut DNA at a highly precise, chosen location in a genome and nowhere else. Genomic DNA breaks are repaired naturally by the DNA maintenance system present in all living organisms. Cellectis combines the ability of meganucleases to cut DNA at a single, chosen location with natural DNA repair, in order to offer new-generation products for a wide spectrum of applications in three targeted markets: human health, agrobiotech, and bioproduction. Cellectis is also pro-actively spreading its technology as a research tool.
In the long term, Cellectis intends to become the global leader in genome engineering. To this end, Cellectis is seeking to establish its rational genome engineering approach (based on meganucleases with modified specificity) as an industry standard. In the short and medium term, Cellectis intends to achieve profitability by commercializing its technology (primarily in the agrobiotech and bioproduction fields) and, in parallel, building its own therapeutic pipeline (thus providing shareholders with medium- and long-term value).

To date, Cellectis has entered into more than 45 deals on its genome engineering technologies with major players in the pharma, biotech and agrobiotech industries. Cellectis is listed on the NYSE-Euronext Alternext market (ticker code: ALCLS). The company currently has 45 staff, including 17 PhDs.
For more information on Cellectis, visit our web site: www.cellectis.com.