1. Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, 660 S. Euclid Ave., St. Louis, Missouri 63110, United States
2. Medical Scientist Training Program, Washington University in St. Louis, 660 S. Euclid Ave., St. Louis, Missouri 63110, United States
3. Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States