1 Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, 37 Guoxue Lane Chengdu, 610041 Sichuan, People's Republic of China.
2 Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, 37 Guoxue Lane Chengdu, 610041 Sichuan, People's Republic of China. Electronic address: yangli_hx@scu.edu.cn.