CD4 and tuberculosis: Regarding the murine model of TB, several authors have shown that mycobacterial Ag‐specific T cells, which are IFN‐γ producers, are constantly moving from lymphoid tissue to the lungs during Mtb infection, suggesting that effector CD4+ and CD8+ T cells can circulate through the bloodstream.15, 16 Accordingly, we need to increase our understanding of the role that CD8+ T cells play in TB, because this cell population could be relevant for the development of new vaccines and immunotherapies, and could possibly be used as a marker of disease progression.