1. Departments of Biochemistry & Biophysics and Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
2. Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, St. Louis, Missouri 63130, United States
3. Medical Scientist Training Program, Washington University in St. Louis, St. Louis, Missouri 63130, United States
4. School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, Irvine, California 92697, United States