1. Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA.
2. California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158, USA.
3. Department of Bioengineering and Program in Bioinformatics, University of California–San Diego, La Jolla, CA 92093, USA.
4. Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
5. Howard Hughes Medical Institute, San Francisco, CA 94158, USA.