1 RG Adipocytes & Metabolism, Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Center Munich, Neuherberg, Germany.
2 German Center for Diabetes Research (DZD), Neuherberg, Germany.
3 RG Adipocytes & Metabolism, Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Center Munich, Neuherberg, Germany siegfried.ussar@helmholtz-muenchen.de.
4 Department of Medicine, Technische Universität München, Munich, Germany.