1. Division of Gastroenterology, Department of Translational Research and New Technology in Medicine and Surgery; University of Pisa; Pisa Italy
2. Division of Gastroenterology, Department of Surgery, Oncology and Gastroenterology; University of Padua; Padua Italy
3. Department of Gastroenterology; CHU Bordeaux and Bordeaux University; Bordeaux France
4. Barts and the London School of Medicine and Dentistry; Queen Mary University of London; United Kingdom
5. Division of Gastroenterology; Washington University School of Medicine; St. Louis Missouri