1 Department of Internal Medicine IV, Division of Endocrinology, Diabetology and Nephrology, University Hospital Tübingen, Tübingen, Germany.
2 Institute for Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany.
3 German Center for Diabetes Research (DZD e. V.), Neuherberg, Germany.
4 Joint Heidelberg-Institute for Diabetes and Cancer (IDC) Helmholtz Center Munich Translational Diabetes Program, Department of Internal Medicine, Heidelberg University Hospital, Heidelberg, Germany.