1. Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health , Bethesda, MD, USA
2. Digestive Oncology Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences , Tehran, Iran
3. Liver and Pancreaticobilliary Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences , Tehran, Iran
4. Center for Tobacco Products, Food and Drug Administration , Silver Spring, MD, USA
5. Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , Atlanta, GA, USA
6. Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences , Gorgan, Iran
7. Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health , Bethesda, MD, USA
8. Department of Biology, School of Computer, Mathematical and Natural Sciences, Morgan State University , Baltimore, MD, USA
9. Stony Brook Cancer Center, Stony Brook University , Stony Brook, NY, USA
10. Department of Medical and Surgical Sciences, University of Bologna , Bologna, Italy
11. International Agency for Research on Cancer , Lyon, France