The full texts were evaluated, and 47 additional articles were excluded because of the following reasons: duplication (two), meta-analysis (seven), review (twelve), discussion on polymorphism in other diseases (tegumentary leishmaniasis and leprosy) (two), other SNPs in IFNG (one), IFNG receptor gene polymorphisms (fifteen), and other genes (three), and lacked case-control study (five). Here, IFNG is linked to leprosy.