1. Department of Pathology, Stanford University Medical School, Stanford, CA 94305, USA.
2. Department of Pharmaceutics and Medicinal Chemistry, University of the Pacific, Stockton, CA 95211, USA.
3. Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
4. Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
5. Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA.
6. The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.