EGF and central nervous system cancer: A meta-analysis with 21 case-control studies containing 5,768 cases and 8,841 controls has investigated the relationship between the EGF +61G/A polymorphism and risk of many types of cancers, the results found that the +61G/A polymorphism was associated with the risk of gastric cancer, esophageal cancer, hepatoma and glioma, but not melanoma and breast cancer [10].