1. 2nd Department of Internal Medicine-Gastroenterology, Charles University, Faculty of Medicine in Hradec Kralove and University Hospital, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
2. Department of Medical Biochemistry, Charles University, Faculty of Medicine in Hradec Kralove, Zborovska 2089, 500 03 Hradec Kralove, Czech Republic
3. The Royal Marsden Hospital NHS Foundation Trust, Fulham Road, Chelsea, SW3 6JJ London, UK