The T>A single nucleotide polymorphism (SNP) of IFNG in the +874 position is one of the best studied polymorphisms that affect the IFN-γ production [9], and it has been associated both with the occurrence of active TB [10] and with lower IFN-γ production in TB patients [9] and in BCG-vaccinated children [11]. Here, IFNG is linked to tuberculosis.