1. Department of Gastroenterology Beijing Friendship Hospital Capital Medical University BeijingChina
2. Beijing Key Laboratory for Precancerous Lesion of Digestive Diseases Beijing China
3. National Clinical Research Center for Digestive Diseases Beijing China
4. Department of Anesthesiology Beijing Friendship Hospital Capital Medical University BeijingChina
5. Department of Pathology Beijing Friendship Hospital Capital Medical University BeijingChina