Moreover, a study of the SLC11A1 gene in African-American and American Caucasian populations indicates that there are two TB susceptibility SNPs—rs17221959 and rs3731863—in the Caucasian population, while rs3731865 is susceptible to TB in the African-American population; nevertheless, these SNP loci do not appear in the (GT)9 repeat sequence allele, the TGTG deletion, and the 3′UTR of the SLC11A1 gene promoter region [33]. Here, SLC11A1 is linked to tuberculosis.