1. Department of Endoscopy Center, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China
2. The Third Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
3. Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
4. Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA