Second, the DNA sequence containing the +874 T allele is the specific binding site for NF-κB.21 NF-κB knockout mice have been shown to have low values of IFN-γ and an increased susceptibility to infection.22 This polymorphism leading to the dysfunction of NF-κB pathway may cause oxidative damage, which also can increase the risk of cancer.21 Indeed, our finding is consistent with previous meta-analysis that T allele is a protect genotype among patients in breast cancer, cervical cancer, asthma, and leprosy.23–26. Here, IFNG is linked to leprosy.