1. Unit of Endocrinology and Metabolism, University of Louvain, Faculty of Medicine, Brussels, Belgium
2. Institut National de la Santé et de la Recherche Médicale U342, St. Vincent de Paul Hospital, Paris, France
3. Department of Endocrinology and Metabolism, Hebrew University Hadassah Medical Center, Jerusalem, Israel
4. Metabolism Unit, CNR Institute of Clinical Physiology, University of Pisa, Pisa, Italy
5. Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois
6. Department of Molecular Medicine, Division of Endocrinology & Diabetes, Karolinska Hospital, Stockholm, Sweden