Furthermore, previous studies including Rv2031c-induced cytokine response, showed conflicting results with one study reporting higher concentrations of IFN-γ, IL-10, and TNF-α in TB exposed individuals compared to healthy controls (Belay et al., 2015) and other studies failing to show IFN-γ responses induced by this antigen (Goletti et al., 2010; Hozumi et al., 2013). This evidence concerns the gene IFNG and tuberculosis.