1. Gastroenterology, Endoscopy Unit, IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy
2. Department of Biomedical Sciences, Humanitas University, 20072 Pieve Emanuele, Italy
3. Gastroenterology Unit, Department of Clinical Medicine and Surgery, University Federico II of Naples, 80126 Naples, Italy
4. Department of General Internal Medicine and Gastroenterology, Evangelisches Krankenhaus, 40217 Düsseldorf, Germany