In chronic hepatitis C, there are changes in the expression profiles of mediators of the immune response of several interleukins (ILs), such as IL-6, IL-8, and IL-10; interferon γ (IFN-γ); growth transformation factor β (TGF-β); C-reactive protein (CRP), and tumor necrosis factor α (TNF-α), factors linked to immunological tolerance, such as forkhead box P3 (FOXP3) (Amoras et al., 2016; de Souza-Cruz et al., 2016; Moura et al., 2019; R-Viso et al., 2010; Sofian et al., 2012). The gene discussed is IFNG; the disease is chronic hepatitis C virus infection.