Both macrophages (MΦ) and dendritic cells (DCs) are important in the defence against M. tb infection, participate in the initiation of early innate immune responses to mycobacterial infections, and APCs process and present TB antigen to both CD4+ (via MHC-II) and CD8+ T cells (via MHC-I) to trigger specific cellular responses. This evidence concerns the gene CD8A and tuberculosis.