CD4 and tuberculosis: This 540 amino acid long antigen, activates dendritic cells51 and macrophages through the TLR4/NF-κB signalling pathway52 and induces strong CD4+ T cell responses.47 Due to high conservation between human and mycobacterial heat shock proteins, peptides presented by MHC molecules might induce cross-reactivity of T cells that would break tolerance that could lead to autoimmunity.53 Therefore, GroL2 epitopes should be carefully considered when designing vaccines against TB, even though they are presented by MHC-II molecules in infected macrophages.