1. Division of Gastroenterology and Hepatology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China
2. Department of Clinical Oncology, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China
3. Institute of Digestive Disease, State Key Laboratory of Digestive Disease, Chinese University of Hong Kong, Hong Kong, China
4. Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston
5. Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston
6. Department of Immunology and Infectious Diseases, Harvard University T.H. Chan School of Public Health, Boston, Massachusetts