Although immune correlates of protection against TB in humans have not yet been determined, multifunctional Th1-type T cells (that produce IFN-γ, TNF-α, and IL-2) are considered a major component contributing to protection in animal models (Flynn and Bloom, 1996; Flynn, 2004; Nandakumar et al., 2014; Karp et al., 2015; Coler et al., 2018). The gene discussed is IFNG; the disease is tuberculosis.