The relationship between IFN-γ genes and leukemia was previously studied,9 in addition, a number of studies have attempted to assess associations between IFN-γ +874T/A polymorphism and leukemia risk.10–16 However, a unified conclusion is still unreached, furthermore, most of these studies had insufficient sample sizes of studied populations, which led to lower statistical power. This evidence concerns the gene IFNG and leukemia.