IFNG and tuberculosis: In addition, the level of CD4+ T cells expressing IFN-γ and HLA-DR (CD4+IFN-γ+HLA-DR+ cells) was significantly lower in the TB+HCV+ group (mean = 67.2% ± 6.2) compared to the TB+HCV– group (mean = 73.1% ± 4.7; p = 0.002) (Figure 1E,F).