The synergistic effect of cytokines with various immune cell subtypes including CD4+, CD8+ and NK cells plays a key role in the immune defence of tuberculosis, the most important of which are macrophages, effector CD4+ T lymphocytes and IFN‐γ, which is secreted by Th1 cells and induces macrophage activation.4 The gene discussed is CD4; the disease is tuberculosis.