Press Release

Cellectis S.A. announces the success of its initial public offering on the Alternext market of Euronext Paris.

The offer price is set at €10.25 per share

Demand from institutional investors was over 6 times the number of shares offered

Romainville, France - February the 6^th, 2007 - Cellectis S.A., a biotechnology company specializing in genome engineering and developing a new range of products for the custom rewriting of DNA sequences for the research, healthcare and industrial sectors, today announced the final details of its initial public offering (IPO) on the Alternext market of Euronext Paris. The company also emphasized its satisfaction with the success of the listing.

The offer price has been set at €10.25 per share.

The amount raised includes €2.7 million subscribed (as part of a reserved offering) by financial investors, the company's employees, officers & shareholders and certain individuals having contributed to Cellectis S.A.'s development.

The free float will stand at around 25.3% of the company's share capital. Should the overallotment option be fully exercised, the free float will rise to 28.1% of the share capital.

The offering targeted at institutional investors raised significant interest, with demand (not including current shareholders) representing about six times the allotted amount. Likewise, the retail offering for individual investors was a success, with demand representing over 12.8 million euros in value and more than 5400 orders placed.

Cellectis S.A.'s capital increase will provide the company with additional resources for financing its operations and supporting its growth strategy, which particularly aims at establishing its technology as the benchmark in genome engineering.

"We're delighted with the success of our stock market listing, which opens a new chapter in the life of Cellectis", emphasized André Choulika, the company's co-founder and CEO. "As in the past, we shall continue to work in conjunction with our partners to develop Cellectis and create shareholder value", he added. "We're sitting on a rich seam of growth for the years ahead in the biotech sector and these additional resources will enable us to move up a gear and reinforce and maintain our leading position in the genome engineering market", concluded André Choulika.

"Today, Cellectis has a strong position, a clear strategy and sizeable assets. The company's commercial positioning is well-defined in three markets (human healthcare, agriculture and biomanufacturing). It has a solid intellectual property portfolio and recognized, proven know-how & technology. The company has wisely developed a strong global presence, thanks to the signature of 45 international agreements. Lastly, its business model generates revenue in the short, mid and long term, with the risk spread over our three target markets", added David Sourdive, the company's founder, VP Corporate Development and COO.

"We're delighted with the success of our stock market listing and the demand expressed - the operation was oversubscribed 6-fold by institutional investors and 5.2-fold by private investors!", continued Marc Le Bozec, Cellectis CFO. "The demand for shares can be broken down geographically as follows: 79% from France, 8.5% from the UK, 7% from Scandinavia and 5% from Switzerland and Germany", concluded Marc Le Bozec.

"It has been an exciting experience to see Cellectis spun out of a research lab at the Pasteur Institute in 1999 and then grow, thanks to an exceptional management team which has delivered what it promised - a leading position in genome engineering. It feels as if we're at the start of an adventure - just like in the late 1970s, with companies like Genentech. The funds raised will enable Cellectis to impose its meganucleases as a global standard", stated Christian Policard, Ph.D., Chairman of Cellectis' Board of Directors.

The sole bookrunner and listing sponsor is SOCIETE GENERALE Corporate & Investment Banking, 17, cours Valmy, 92972 Paris-La Défense 7.

Practical information:

About Cellectis S.A.

Cellectis S.A. is a biotech company developing innovative, proprietary technologies for genome engineering: a new class of "molecular scissors" - Meganuclease™ enzymes - capable of recognizing, binding and cutting DNA with extremely high specificity. The company is developing and commercializing Meganuclease Recombination Systems (MRSs) which combine these molecular scissors with a DNA matrix for targeting and modifying a gene of interest in vivo (and without affecting the rest of the genome) via the action of the cell's natural maintenance and repair system. By developing this first-in-class technology on the industrial scale, Cellectis has opened the way to rational genome engineering, which seeks to accurately and reliability insert, modify, modulate or correct genes in any living organism - without the addition of foreign genes, which are often imprecise and poorly tolerated. Cellectis now holds a portfolio of 8 MRSs in development, of which 5 have a therapeutic focus.

Cellectis is a spin-off from the Pasteur Institute in Paris, which has granted the company exclusive rights to 26 of the 27 granted patents and 38 of the 69 pending applications in its current portfolio, including one which will fall into the public domain in 2009, followed by 6 others in 2010. Before its IPO, Cellectis had already raised 17.5 million euros in two rounds (in 2000 and 2002/2005) to support its R&D and commercial development. The company's principal shareholders are AGF Private Equity, BankInvest Biomedical Venture, Edmond de Rothschild Investment Partners, Kaminvest Holding and Odyssée Venture. To date, Cellectis has signed 45 collaboration agreements and alliances worldwide with pharma companies (including AstraZeneca, Merck & Co., Wyeth and Shire), agrochemical groups (including Bayer, DuPont and BASF) and biotech companies (including Genentech, Regeneron and Lexicon Genetics). Cellectis' corporate headquarters are located on the Biocitech biopark at Romainville near Paris. It currently has 40 staff, including 16 PhDs.

For more information on Cellectis, visit our web site: www.cellectis.com

Availability of the prospectus

Copies of the prospectus approved by the French Autorité des Marchés Financiers ("AMF") on January 22^nd, 2007 under visa number 07-023 are available free of charge from Cellectis S.A, 102, route de Noisy, F-93230 Romainville, France, and on the websites of the AMF (http://www.amf-france.org) and Cellectis (http://www.cellectis.com). The French prospectus includes the document de base registered with the AMF on December 22, 2006 under number I.06-198, the note d'opération and a summary thereof.

Risk factors

Cellectis draws the attention of the public to the risks set out in Chapter 4 of the document de base and in Chapter 2 of the note d'opération.

This press release, and the information contained herein, do not constitute an offer to sell or a solicitation of an offer to buy or subscribe for shares in Cellectis in any country.

Shares in Cellectis may not be sold in the United States of America absent registration or an exemption from registration under the U.S. Securities Act of 1933, as amended. There will be no registration of all or part of the offering referred to in this press release in the United States of America nor any public offering of Cellectis in the United States of America. This press release may not be distributed, in particular, either directly or indirectly, in the United States of America and does not constitute an offer to sell securities in the United States of America.