Microsoft Research, One Memorial Drive, Cambridge, MA 02142, USA, Blavatnik School of Computer Science, Tel Aviv University, Tel-Aviv 69978, Israel, Department of Bioengineering and Therapeutic Sciences and Department of Medicine, University of California, San Francisco, CA 94158 and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA Microsoft Research, One Memorial Drive, Cambridge, MA 02142, USA, Blavatnik School of Computer Science, Tel Aviv University, Tel-Aviv 69978, Israel, Department of Bioengineering and Therapeutic Sciences and Department of Medicine, University of California, San Francisco, CA 94158 and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.