1 Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy. Electronic address: alessandro.vitale@unipd.it.
2 Transplant Hepatology Unit, Division of Gastroenterology and Hepatology, IRCCS Cà Granda Maggiore Hospital Policlinico and RC "A. M. and A. Migliavacca" Center for the Study of Liver Disease, University of Milan, Milan, Italy.