1. 1Institute of Physiology, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
2. 2Paul Langerhans Institute Dresden of Helmholtz Munich at the University Hospital and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
3. 3German Center for Diabetes Research (DZD), München-Neuherberg, Germany
4. 4Department of Pathology, Immunology and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL