1. Department of Genetic Medicine and Development (P.A.H.), University of Geneva, 1211 Geneva 4, Switzerland
2. Hormone Research Institute (M.S.G.), Diabetes Center, University of California, San Francisco, San Francisco, California 94143-0534
3. Department of Medicine (S.E.K.), Division of Metabolism, Endocrinology, and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98195
4. Section of Islet Transplantation and Cell Biology (G.C.W.), Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215