Press Release

Cellectis grants TransGenic a non-exclusive license to its homologous recombination technology.

Biocitech, France and Kobe, Japan - October the 15^th, 2007 - Cellectis SA, the rational genome engineering company developing a new range of custom DNA rewriting products for the research, healthcare and industrial sectors, and TransGenic Inc, the tool providing company in the field of pharmaceutical and diagnostic development with its innovative technology of producing genetically engineered mice and a wide variety of antibody products, today announced that they entered into a non-exclusive license agreement under a patent family (JP 3059481, JP 3298842 and JP 3298864) relating to a process for the specific replacement or insertion of a gene in a receiver genome by homologous recombination.

This technology is the world standard in gene targeting and is used to precisely substitute, delete or add genetic sequences at a chosen location in a genome. In particular, it is often used in the life science industry and academic research to generate mouse models with altered genomes to study gene function and/or to mimic human diseases. Such models are commonly used to elucidate the mechanisms of diseases. The technology was invented at the Institut Pasteur, which then granted Cellectis worldwide exclusive rights to the umbrella patent family that covers the platform.

The license agreement grants TransGenic the right to use Cellectis' patented technologies for the generation and commercialization of genetically modified mice. The financial terms and conditions of the agreement were not disclosed.

Cellectis devotes significant efforts to promoting the adoption of its technology as a worldwide standard, wherever it may apply. Cellectis' strong patent position extends to Japan, so this license agreement is a direct implementation of the company's strategy. Cellectis' technologies will thus be inserted into the processes and value chain of the pharmaceutical industry in that territory.

"We are delighted to have signed this license agreement with TransGenic, who will use this powerful, patented technology for the generation of in vivo models for the pharmaceutical industry", commented David J.D. Sourdive, Vice President Corporate Development at Cellectis: " The industry is benefiting greatly from our rational approach, which focuses on targeted (rather than random) modifications. This deal with TransGenic illustrates both our patent position in Japan and our continuing ability to deliver on our objectives and timeline for 2007".

" TransGenic cyclopaedically produces and analyzes a great number of knockout mice by exchangeable gene-trap method and also produces knockout mice by gene targeting method as per requests from pharmaceutical companies and universities. We believe obtaining a widely-applicable technological license for the first time in Japan, which is inevitable to produce and sell knockout mice by gene targeting method, is beneficial for us to expand our future business. This licensing agreement enables researchers using our knockout mice to conduct various researches with a freedom to operate under these umbrella patents. "  commented Masahiro Koreishi, CEO of TransGenic Inc.

About homologous recombination

Homologous recombination relies on the natural cellular DNA maintenance and repair mechanisms present in all living cells and organisms. It is the technological basis for rational genome engineering - Cellectis' core expertise. This robust technology platform is widely used in life sciences, in particular for gene targeting, and has proven its efficacy for over a decade. At present, homologous recombination is a worldwide standard for elucidating gene function and to generate animal models for pharmaceutical and biotechnology industries.

Relevance of the agreement to Cellectis' and TransGenic's approaches:

Cellectis' proprietary rational genome engineering technology was developed thanks to two basic technology sets discovered and patented by Institut Pasteur: naturally occurring meganucleases and homologous recombination. In 2000 Cellectis became Institut Pasteur's exclusive licensee for six technologies including natural meganucleases and homologous recombination. With this strong position, Cellectis creates, develops and patents its own technology, which aims at modifying the specificity of meganucleases so that it can break DNA at a predetermined place.

Cellectis also has the ability to sub-license the basic technology sets to industrial and academic partners in narrowed areas, firstly to spread the technology and establish it as a standard and, secondly, to generate significant revenues through the signature of over 45 agreements. Cellectis grants TransGenic Inc a sub-license to the homologous recombination technology by this agreement.

TransGenic Inc. has developed its business centering on knockout mice and antibodies.

As for the knockout mice business, TransGenic Inc. provides custom production service of knockout mice in whom particular genes are destroyed by gene targeting method. A very basic technology called homologous recombination is necessary to produce the mice and it is protected by a patent. TransGenic Inc. is the first Japanese company to acquire the license under this technology to provide custom production service of knockout mice in Japan. Therefore, researchers who have obtained knockout mice from TransGenic Inc. can conduct various researches without having patent-related problems. The patent also brings a lot of advantages to TransGenic's business.

Meanwhile, technical basis of TransGenic's antibody business is an antibody-producing technology named GANP mouse technology. This technology is to produce high-affinity monoclonal antibodies by the use of mice overexpressing GANP genes. TransGenic Inc. forms a platform of protein-engineering including the GANP mouse technology and grants licenses to pharmaceuticals and diagnostic reagents manufacuturers. In addition, TransGenic Inc. has also developed its original products in the field of cancer, diabetes and metabolic syndrome.

About Cellectis:

Cellectis SA (www.cellectis.com) is a world-leading company in genome engineering and genome surgery. The company is focused 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 repair naturally by the DNA maintenance system present in all living organisms. Cellectis combines the capacity of meganucleases to break DNA at a unique and chosen location with natural DNA repair to propose new generations of products for a wide spectrum of applications:

• Human health: Meganucleases that target a gene responsible for a genetic disease are transferred into human cells together with a DNA repair matrix, which includes the right sequence of the mutated gene. After DNA break (few minutes) the right sequence is copied into the genome of the patients' cells and the gene is repaired. This process, termed 'genome surgery', provides an action limited in time, with permanent effects and all transferred material is degraded by natural mechanisms.
  
  
• Agrobiotech: The same process as for human health can be applied to plants with the objective to replace one gene by another, modify it or shut it down. The applications developed using Cellectis' technology are essentially to improve agronomic features of crops, produce new generations of biofuels and develop improved biofibers.
  
  
• BioProduction: BioProduction is the production of therapeutic proteins and antibodies using bacteria, yeasts or mammalian cells (mouse, hamster and human cells). This multi-billion market has an annual growth rate above 15%. Cellectis has developed meganucleases that cut DNA of major production cell lines used in BioProduction enabling the end users (contract manufacturing organizations or biopharmaceutical companies) to shorten their cell line engineering processes, stabilize production yields thus quality of the final product and improve final product features.

On the long term Cellectis aims at a worldwide leader position in genome engineering. To this end, Cellectis intends to establish its rational genome engineering approach based on meganucleases with modified specificity as a standard. On the short and medium term Cellectis intends to reach profitability by commercializing its technology mostly in the agrobiotech and BioProduction and in parallel to build its own therapeutic pipeline, which will provide medium and long term upside to its shareholders.

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 Euronext Alternext market (ticker code: ALCLS). For more information on Cellectis, visit our web site: www.cellectis.com

Cellectis' Forward-Looking Statements

This communication expressly or implicitly contains certain forward-looking statements concerning Cellectis and its business. Such statements are based on assumptions and assessments made by Cellectis' management in light of their experience and their perception of historical trends, current conditions, expected future developments and other factors they believe to be appropriate. They are not guarantees of Cellectis' future performance and involve certain known and unknown risks, uncertainties and other factors, which could cause the actual results, financial condition, performance or achievements of Cellectis SA to be materially different from any future results, financial condition, performance or achievements expressed or implied by such forward-looking statements. Cellectis is providing this communication as of this date and does not undertake to update any forward-looking statements contained herein as a result of new information, future events or otherwise. Potential risks and uncertainties which could cause actual results, financial condition, performance or achievements of Cellectis SA to differ from those contained in the forward-looking statements include, without limitation, the risks and uncertainties discussed in the Risk Factors (Facteurs de risques) sections of the prospectus prepared by Cellectis approved by the French Autorité des Marchés Financiers ("AMF") on January 22^nd, 2007 under visa number 07-023, available on the websites of the AMF (http://www.amf-france.org) [and Cellectis (http://www.cellectis.com)].

About TransGenic:

TransGenic Inc.(www.transgenic.co.jp), based in Japan, is a tool providing company in the field of pharmaceutical and diagnostic development with its innovative technology of producing genetically engineered mice and a wide variety of antibody products.

As one of the leading companies in Japan in the field of knockout mice, TransGenic Inc. provides custom production service of knockout mice in whom particular genes are destroyed by gene targeting method. This service is based on high-quality ES cells and advanced technologies of cell cultivation and embryological engineering

TransGenic Inc. owns TG resource bank, libraries of approximately 700 knockout mice strains and 2,000 lines of ES cells cyclopaedically produced in a large scale by exchangeable gene trapping method. TransGenic Inc. discovers and identifies innovative drugable targets based on information in the libraries. These information is integrated in a public database as well as offered to and used by over ten pharmaceutical companies including Astellas Pharma Inc. and Sumitomo Chemical Co., Ltd. Not only the information in the libraries but the mice themselves are also widely offered as research tools to reseachers at home and abroad.

TransGenic Inc. possesses an unique technology of high-affinity antibody production using GANP(R) mice, and conducts business worldwide with this technology. TransGenic Inc. also provides various antibody products as research reagents. Product lineups include; Bio-markers for environmental hormones (Vitellogenin ELISA kit), novel tumor marker in urine (Diacetylspermine ELISA Kit), antibodies related to amino acid transporters, advanced glycation end products.

• TG resource Bank: Large scale and cyclopaedic libraries of knockout mice/ES clones produced by unique "gene-trap" technology covered by our patent (WO01/005987) for discovering innovative drug targets. The libraries provide information on gene function beneficial to accelerate identification of novel prospective drugable targets.
  
  
• GANP(R) mouse: A transgenic mouse overexpressing murine ganp gene. The mouse enables us to produce monoclonal antibodies with an unprecedented level of high affinity. This technology has been covered by a patent of Immunokik Inc.(WO00/50611, WO2004/040971) and TransGenic Inc. has held an exclusive license with a sublicense of the patent.After immunization of T cell-dependent Antigen, a GANP-transgenic mouse augments induction of somatic hypermutation in V-regions, resulting in affinity maturation of the V regions during proliferation and differentiation of antigen-driven B cells. In consequence, it is highly possible that high-affinity monoclonal antibodies can be obtained by the use of a GANP-transgenic mouse.
  
  
• Novel urine tumor marker: TransGenic Inc. has successfully developed highly specific monoclonal antibody against diacetylspermine which can be used for a novel urine tumor marker. Wehave a patent (JP3816512) in Japan but have filed an application(U.S. 11/263,355) in U.S. on a highly sensitive immunological assay system for cancer diagnosis using urine samples. Licensing the patent of this technology to several diagnostic reagent manufacturers is now under negotiation.

TransGenic Inc. is listed on the Tokyo Stock Exchange (Mothers Section). (ticker code:2342).
For more information on TransGenic Inc., visit our web site: www.transgenic.co.jp