CD4 and tuberculosis: Given the crucial roles of innate and adaptive immunity in TB defense (28), particularly CD4+ T cells and CD8+ T cells (29), there is substantial evidence supporting the notion that CD4+ T cells release cytokines, such as interferon-γ (IFN-γ) in response to specific antigens of mycobacterial to enhance phagocytosis of macrophage to control TB (30).