1. Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Division of Gastrointestinal Cancer Translational Research Laboratory Peking University Cancer Hospital & Institute Beijing 100142 P. R. China
2. Department of Pathology Peking University Cancer Hospital & Institute Beijing 100142 P. R. China
3. The Tissue Bank Peking University Cancer Hospital & Institute Beijing 100142 P. R. China
4. Department of Molecular Diagnosis Peking University Cancer Hospital & Institute Beijing 100142 P. R. China
5. Department of Gastrointestinal Surgery Peking University Cancer Hospital & Institute Beijing 100142 P. R. China