1. 1Duke Molecular Physiology Institute, Duke University, Durham, NC
2. 2Division of Endocrinology, Department of Medicine, Duke University, Durham, NC
3. 3Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, VA Puget Sound Health Care System and University of Washington, Seattle
4. 4Unit of Molecular Metabolism, Lund University Diabetes Centre, Malmö, Sweden