1. Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
2. Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
3. Department of Medicine, University of California, San Diego, La Jolla, California 92093, United States
4. Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, United States