Taking into account that i) PD-Ls were highly expressed in PE cells from TB patients; ii) M1 macrophages were more susceptible to cytotoxic killing by CD8+ T cells, and iii) that PD-1 pathway blockade enhanced cytotoxicity and IFN-γ production by PEMC from TB patients as observed elsewhere22, we aimed to study the modulatory role of PD-1/PD-Ls pathway on CD8+ T cell-driven antigen-specific cytotoxicity. This evidence concerns the gene IFNG and tuberculosis.