1. Diabetes Unit, Section of Endocrinology, Boston Medical Center, and Departments of Medicine and Physiology, Boston University School of Medicine, Boston, Massachusetts
2. Copenhagen Muscle Research Centre, Centre of Inflammation and Metabolism Rigshospitalet, Copenhagen, Denmark
3. Obesity Research Unit, Boston University School of Medicine, Boston, Massachusetts
4. Institute of Neurosciences and Department of Cellular Biology, Physiology, and Immunology, Animal Physiology Unit, Faculty of Sciences Universidad Autónoma de Barcelona, Barcelona, Spain
5. Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania