1. State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, the Fourth Military Medical University, Xi’an, China;
2. Department of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi’an, China;
3. Department of Gastroenterology, the 16th Hospital of the People’s Liberation Army of China, A Letai, China;
4. Air Force General Hospital of the People’s Liberation Army of China, Beijing, China;
5. Department of Gastroenterology, Xi’an Central Hospital, Xi’an, China