1. Department of Internal Medicine, Fondazione Policlinico Universitario A. Gemelli IRCSS, Rome, Italy
2. CNR-Institute of Systems Analysis and Computer Science, BioMatLab, Rome, Italy
3. Department of General Surgery, Fondazione Policlinico Universitario A. Gemelli IRCSS, Rome, Italy
4. Department of Medicine III, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Dresden, Germany
5. Division of Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
6. Paul Langerhans Institute Dresden, Helmholtz Center Munich, University Hospital Dresden, a Member of the German Center for Diabetes Research, Dresden, Germany