1 Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
2 Gastroenterology and Endoscopy Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
3 Division of Gastroenterology and Hepatology, CRC "A. M. and A. Migliavacca" Center for the Study of Liver Disease, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.