1. Hospital Clinic de Barcelona – Endoscopy Unit, Barcelona. University of Barcelona, Spain
2. CIBEREHD Barcelona, Spain
3. IDIBAPS – Medicina, Barcelona, Spain
4. Hospital of Imola – GI Unit, University of Bologna, Imola, Italy
5. University of Medicine and Pharmacy – Regional Institute of Gastroenterology and Hepatology, Cluj-Napoca, Romania
6. Hospital Universitario de de Sta Cruz de Tenerife – Service of Gastroenterology, Tenerife, Spain
7. Hospital Clinic de Barcelona – Pathology Department, University of Vic – Central University of Catalonia (UVic-UCC), Barcelona, Spain