1. Cardiff China Medical Research Collaborative, Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
2. Department of Histopathology, Morriston Hospital, Heol Maes Eglwys, Swansea SA6 6NL, UK
3. Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Gastrointestinal Tumour Center, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China