1. Endoscopic Unit, Department of Gastroenterology and Hepatology at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
2. Department of Pathology at Tongji Hospital, Tongji Medical College, HUST, Wuhan, China
3. Tongji Medical College, HUST, Wuhan, China
4. Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, HUST, Wuhan, China