1. Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
2. Department of Pathology, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Korea
3. Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200001, China
4. Department of Surgical Oncology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
5. Department of Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
6. Department of Human Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
7. Division of Cancer Etiology, Peking University Cancer Hospital and Institute, Beijing 100142, China
8. Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China