1. Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
2. Gastroenterology Unit, Avellino Hospital, Avellino, Italy
3. Department of Medicine, Vittorio Emanuele III Hospital, Salemi, Italy
4. Department of Gastroenterology and Digestive Endoscopy, Academic Hospital Cattinara, Trieste, Italy
5. Centre of Regenerative Medicine, Humanitas Mater Domini, Castellanza, Varese, Italy
6. Gastroenterology Unit, University of Palermo, Palermo, Italy
7. Department of Gastroenterology and Digestive Endoscopy, Buccheri la Ferla, Fatebenefratelli Hospital, Palermo, Italy