1. Genomic Epidemiology Branch, International Agency for Research on Cancer (IARC/WHO), 69007 Lyon, France
2. Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan 49341-74515, Iran
3. Environment and Lifestyle Epidemiology Branch, International Agency for Research on Cancer (IARC/WHO), 69007 Lyon, France
4. Digestive Oncology Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran 14117-13135, Iran