The internal mechanisms of the body's immune system in fighting pathogenic infections involve the secretion of pro-inflammatory cytokines, namely interferon gamma (IFN-γ), interleukin-2 (IL-2), tumor necrosis factor α (TNF-α), lymphotoxin, and granulocyte-macrophage colony-stimulating factor, which are mediated by T helper cells (Th1) (Raphael et al., 2015). This evidence concerns the gene IFNG and infection.