1. Department of Medical and Surgical Sciences University of Bologna Bologna Italy
2. Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics National Cancer Institute Bethesda Maryland USA
3. Digestive Oncology Research Center, Digestive Diseases Research Institute Tehran University of Medical Sciences, Shariati Hospital Tehran Iran
4. Golestan Research Center of Gastroenterology and Hepatology Golestan University of Medical Sciences Gorgan Iran
5. Department of Biology, School of Art and Sciences Utica College Utica New York USA
6. Department of Biology, School of Computer, Mathematical, and Natural Sciences Morgan State University Baltimore Maryland USA
7. Section of Genetics International Agency for Research on Cancer Lyon France
8. Stony Brook Cancer Center Stony Brook University Stony Brook New York USA