1. Informatics and Bio-computing Platform, Ontario Institute for Cancer Research, Toronto, ON M5G0A3, Canada
2. Division of Biology and Biological Engineering 156–29, California Institute of Technology, Pasadena, CA 91125, USA
3. European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
4. Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
5. Department of Genetics, Washington University School of Medicine, St Louis, MO 63110, USA