1 Department of Pathology, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
2 1] Department of Pathology, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China [2] Department of Pathology, Chengde Medical College, Chengde, China.
3 Department of Endoscopy, Cancer Institute (Hospital), Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
4 1] Department of Pathology, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China [2] Department of Pathology, Beijing Chaoyang Hospital, Beijing, China.
5 Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.