Disclosure

Cellectis launch new program with Bayer Cropscience for uses of Meganuclease technology in crops.

Biocitech, France - November the 6^th, 2007 - Cellectis SA, the French rational genome engineering company, disclosed today the launch of a new program with Bayer CropScience using Cellectis' proprietary custom-made Meganuclease technology in plants to develop products for use in agriculture.

Meganucleases are a proprietary genome engineering technology developed by Cellectis that allows highly precise 'editing' of genetic sequences. They consist of sequence-specific endonucleases with large (>18-24 bp) recognition sites. This high specificity ensures Meganucleases can bind and cut at a single point in a chosen genome, avoiding the imprecision associated with most other forms of gene modification. Custom-made Meganucleases can be designed for very specific gene targeting applications, which include genomic sequence addition, modification or deletion.

Cellectis and Bayer Cropscience already had an ongoing collaboration for specific targets in plants since 2006. This new program includes the design of engineered Meganucleases specifically customized to recognize new chosen targets in crop genomes.
Targets and terms of the collaboration were not disclosed.

" This new program comforts our presence in the Agrobiotech field. It strengthens our collaboration with Bayer and confirms our strategy." Commented David J.D. Sourdive, Vice President Corporate Development of Cellectis. "We are delivering as planned and are thus successfully implementing our business model."

About the agreement

Meganucleases can induce precise, surgical changes in crop genomes and have the capacity to be the next break-through enablement for increasing crop yield and creating new plant-based products for Bayer CropScience's customers.

Agronomic applications are a clear segment of the Cellectis' markets and the collaboration with Bayer is part of its efforts to see that its proprietary Meganuclease technology be implemented in plants. This new program is in direct line with Cellectis' strategy.

Cellectis' Forward-Looking Statements

This disclosure 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 disclosure 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)].