1 Department of Gastroenterology and Hepatology, Institute for Clinical and Experimental Medicine, Videnska 9, 140 21, Prague 4, Czech Republic. Electronic address: tomas.hucl@ikem.cz.
2 Gastroenterology Department, Oncology Portuguese Institute of Porto, Portugal; CIDES/CINTESIS, Faculty of Medicine, University of Porto, Portugal.
3 Institute of Gastroenterology and Liver Diseases, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Israel. Electronic address: ian_gr@clalit.org.il.
4 Asian Institute of Gastroenterology, 6-3-661, Somajiguda, Hyderabad 500 082, India.