[1] Sichuan Univ, West China Hosp, Lab Gastroenterol & Hepatol, Chengdu, Peoples R China
[2] Shanghai Jiao Tong Univ, Renji Hosp, Shanghai Inst Digest Dis, Sch Med,Div Gastroenterol & Hepatol,Natl Hlth Comm, Shanghai, Peoples R China
[3] Air Force Mil Med Univ, Natl Clin Res Ctr Digest Dis, State Key Lab Canc Biol, Xian, Peoples R China
[4] Air Force Mil Med Univ, Xijing Hosp Digest Dis, Xian, Peoples R China
[5] Mayo Clin, Div Gastroenterol & Hepatol, Rochester, MN 55905 USA