1. Division of Endocrinology, Metabolism and Diabetes and Program in Human Molecular Biology and Genetics (E.D.A., C.G., S.B., M.P.), University of Utah School of Medicine, Salt Lake City, Utah 84112
2. Nuffield Department of Clinical Medicine (P.A.R.), University of Oxford, John Radcliffe Hospital II, Headington OX3 9DU, United Kingdom
3. Department of Biochemistry (V.K., T.K., Z.X., K.V.K.), Boston University School of Medicine, Boston, Massachusetts 02118