In the first study executed of this SNP, the association of the SNP in the IL23R gene with leprosy in the Chinese population, with a sample size of 3,301 patients and 5,299 individuals without the disease, in which the frequency of the AA genotype was 83%, and the analyses indicated an association with protection against leprosy (OR = 0.69, p = 3.27 × 10− 11) [18], as also demonstrated in the study carried out in southwest China (OR = 0.42, 95% CI = 0.26–0.68, p = 3.2E-04) [16]. The gene discussed is IL23R; the disease is leprosy.