1 Academic Medical Centre, Department of Gastroenterology and Hepatology, Room C2-325, PO Box 22700, 1100 DE Amsterdam, The Netherlands. Electronic address: a.j.bredenoord@amc.uva.nl.
2 Northwestern University, Feinberg School of Medicine, Division of Gastroenterology and Hepatology, 676 St Clair Street, Suite 1400, Chicago, IL 60611-2951, USA. Electronic address: I-hirano@northwestern.edu.