Press Release

Celonic and Cellectis announce a commercial license agreement following key milestone in meganuclease-mediated cell line engineering for biomanufacturing.

Basel, Switzerland and Romainville, France - April the 3^rd, 2007 - Celonic AG (a contract biomanufacturing organization) and Cellectis SA (the rational genome engineering company) announced a key milestone in their collaboration focused on engineering a cell line for biomanufacturing bearing a tagged "hot spot" for fast generation and high expression.

High-performance producer cells have become a major issue in therapeutic recombinant protein production. Most current methods rely on random transgenesis followed by extensive screening for favorable transgene integration into privileged genomic loci ("hot spots"). A targeting system has now been developed in order to rationalize the process. Scientists at Celonic and Cellectis have collaborated to identify a "hot spot" of this type, opening the way to higher yields in the production of recombinant proteins. A master producer cell line has been derived and any transgene can now be reproducibly targeted into the same "hot spot" through meganuclease-induced recombination. Following achievement of this successful technical milestone, Celonic is being granted a commercial license to the cell line using Cellectis' meganuclease technology. Financial terms were not disclosed.

David Sourdive, co-founder and Vice President Corporate Development at Cellectis, commented: "This is a major milestone for our meganuclease recombination systems, and we are delighted with Celonic's success. With this new meganuclease-based tool, cell line development is now reproducible and more efficient and improves bio-manufacturing processes. It is in line with our efforts to provide robust cell and genome engineering products which deliver value to the bio-manufacturing industry."

Meganucleases are biotechnological tools for performing precise gene insertion, modulation, deletion or substitution in any living cell.

"We are very pleased about achieving these collaboration milestones, which put us into a leading position in Cell line engineering for the production of biopharmaceuticals", said Andreas Herrmann, CEO of Celonic. "This innovative technology will dramatically reduce time to clinic and market for any biopharmaceutical protein produced in mammalian cells".

About Celonic:

Celonic (www.celonic.com) is a globally-active contract manufacturing organization offering Cell line and process development, as well as the GMP production of cell banks & recombinant proteins for clinical phases & market supply. In addition, Celonic has built up its own pharmaceutical platform for the development of biopharmaceuticals for the treatment of immune diseases.

About Cellectis:

Cellectis SA (www.cellectis.com) is a world leading company in genome engineering and genome surgery. The company is focused on developing custom-made meganucleases for in vivo DNA surgery and also provides new tools for rational reverse genetics and targeted recombination. Cellectis' products can induce unique site-directed double-strand DNA breaks in a living cell and are used for biotechnological and therapeutic applications. 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 (ticjer code: ALCLS).