1. Clinic of Gastroenterology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
2. Gastroenterology and Endoscopy Unit, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
3. Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
4. Department of Pediatric Gastroenterology, University of Helsinki and Children’s Hospital, Helsinki, Finland