Department of Medicine for EndocrinologyDiabetes and Nutritional Medicine, Charité Universitätsmedizin, Berlin, Germany. Department of EndocrinologyNational Institute of Endocrinology and Diabetology, Lubochna, Slovakia. Department of Internal Medicine VUniversity Hospital Ruzinov, Bratislava, Slovakia. Department of EndocrinologyUniversity Medical Centre Ljubljana, Ljubljana, Slovenia. Neuroendocrine UnitClinical Centre of Serbia, Belgrade, Serbia. 1st Department of MedicineUniversity of Pécs, Pécs, Hungary. 2nd Department of Internal MedicineMilitary Hospital - State Health Center, Budapest, Hungary. II Internal Clinic in University Hospital St AnnaBrno, Czech Republic. I Department of Internal MedicineUniversity Hospital Bratislava, Bratislava, Slovakia. 1st Department of Internal MedicineHetényi Géza Hospital and Out-Patient Clinic, Szolnok, Hungary. OPKO BiologicsKiryat Gat, Israel. Medizinische Klinik - InnenstadtLudwig Maximilian University, Munich, Germany. Neuroendocrine UnitMassachusetts General Hospital, Boston, Massachusetts, USA.