1. Faculty of MedicineUniversity of BelgradeBelgradeSerbia
2. Digestive Endoscopy UnitUniversity Clinic ‘Dr Dragisa Misovic‐Dedinje’BelgradeSerbia
3. Department of CancerKarolinska University HospitalStockholmSweden
4. Department of Gastroenterology and Digestive EndoscopyMater Olbia HospitalOlbiaItaly
5. CLINTECKarolinska InstitutetStockholmSweden