Yet, effector CD8+ T-cells are known to secrete cytolytic and antimicrobial factors that kill Mtb-infected macrophages in vitro (49), inhibit Mtb growth (47), and are required for long-term infection control in mice (50) and humans (51); perforin production by CD8+ T-cells is also higher in treated than in untreated TB patients (52). This evidence concerns the gene PRF1 and tuberculosis.