1. Department of Gastroenterology, Union Hospital, Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China
2. Department of Gastroenterology, The First Affiliated Hospital of Xiamen University, School of Medicine Xiamen University Xiamen China
3. Department of Pathology The People's Hospital of Guangxi Zhuang Autonomous Region Nanning 530021 Guangxi Zhuang Autonomous Region China
4. Department of Gastroenterology, The First Affiliated Hospital Sun Yat‐sen University Guangzhou 510080 China