1. Department of Gastroenterology, the Fifth Clinical Center of Chinese PLA General Hospital (307 Hospital), Beijing, China
2. Department of Internal Medicine, Clinic of August First Film Studio, Beijing, China
3. Department of Gastroenterology and Hepatology, the People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
4. Department of Gastroenterology, the Second Affiliated Hospital of Soochow University, Suzhou, China
5. Department of Gastroenterology and Hepatology, Shanghai Tenth People’s Hospital, Shanghai, China
6. Department of Gastroenterology, the Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.