Protection against active TB is known to require a clearly delineated T-helper type 1 (Th1) response, mediated by interferon-gamma (IFNγ), interleukin-2 (IL2), and tumor necrosis factor-alpha (TNFα) [35–37], which may clear infection or drive it into an immune-mediated containment or latency. This evidence concerns the gene IL2 and tuberculosis.