1. European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK.
2. Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA.
3. Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, E-08003 Barcelona, Spain.
4. EMBL, Genome Biology Unit, 69117 Heidelberg, Germany.