1. Division of Endocrinology (G.B.A., X.H., M.G.G., M.A.L.), Diabetes, and Metabolism Departments of Medicine and Genetics, and The Penn Diabetes Center University of Pennsylvania School of Medicine Philadelphia, Pennsylvania 19104
2. Cell Biology Program (C.R., L.P.F.) Memorial Sloan-Kettering Cancer Center New York, New York 10021