1. Departments of Biomedical Sciences and Internal Medicine, Genome Research Center for Diabetes and Endocrine Disease, Seoul National University College of Medicine, 28 Yongon-Dong, Seoul 110-799, Korea, Institute of Medical Science, Ajou University School of Medicine, Wonchon-dong, Suwon, Kyunggi-do, 442-749 Korea, and Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Songdo-dong, Incheon 406-840, Korea