1. Institut fuer Diabetesforschung der Forschergruppe Diabetes e.V. at the Helmholtz Center Munich (C.W., K.K., A.-G.Z.), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
2. Institute of Epidemiology (T.I.), Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
3. Center for Regenerative Therapies (E.B.), Dresden University of Technology, Biotechnology Center, Tatzberg 47/49, 01307 Dresden, Germany
4. Forschergruppe Diabetes der Technische Universitaet Muenchen (A.-G.Z.), Koelner Platz 1, 80804 Munich, Germany