1 Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China; Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China.
2 Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
3 Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. Electronic address: heyao@mail.sysu.edu.cn.