1 Department of Gastroenterology, National Clinical Research Center for Digestive Diseases, State Key Laboratory of Digestive Health, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China.
2 Department of Gastroenterology, National Clinical Research Center for Digestive Diseases, State Key Laboratory of Digestive Health, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China. sunxiujing@ccmu.edu.cn.