Centre for Computational Biology, Mines ParisTech, Fontainebleau F-77300, Institut Curie, U900, INSERM, Paris, F-75248, France, Department of Genome Sciences and Department of Computer Science and Engineering, University of Washington, Seattle, WA 98195, USACentre for Computational Biology, Mines ParisTech, Fontainebleau F-77300, Institut Curie, U900, INSERM, Paris, F-75248, France, Department of Genome Sciences and Department of Computer Science and Engineering, University of Washington, Seattle, WA 98195, USA.