1 Helmholtz Zentrum München, Institute of Diabetes and Regeneration Research, Parkring 11, 85748 Garching, Germany.
2 German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
3 Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.