1. Institute of Clinical Medicine, National Yang-Ming University, Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, 201 Shih-Pai Road, Sec. 2, Taipei 112, Taiwan, Republic of China
2. Division of Cancer Research, Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan, Republic of China
3. Department of Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
4. Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, Republic of China