[1] IRCCS San Raffaele Sci Inst, Div Expt Oncol, Gastroenterol & Gastrointestinal Endoscopy Unit, Milan, Italy
[2] Univ Vita Salute San Raffaele, Gastroenterol & Gastrointestinal Endoscopy Unit, I-20132 Milan, Italy
[3] Gastroenterol Hosp S De Bellis IRCCS, Gastroenterol Unit 1, Castellana Grotte, Italy
[4] Boston Univ, Sch Med, Boston, MA 02118 USA
[5] Boston Med Ctr, Gastroenterol Sect, I-20132 Milan, Italy