CEA, BIG, Biologie à Grande Echelle, F-38054 Grenoble, France.|Department of Mathematics and Statistics, University of Turku, Turku, Finland.|Plateforme ARN Interférence (PArI), DSV/ISVFJ/SBIGEM/UMR 9198 I2BC, CEA Saclay, Gif-sur-Yvette, France.|Institute of Molecular and Cellular Radiobiology, CEA, Fontenay-aux-Roses, France.|Institute of Molecular and Cellular Radiobiology, CEA, Fontenay-aux-Roses, France.|CEA, BIG, Biologie à Grande Echelle, F-38054 Grenoble, France.