PRF1 and tuberculosis: We previously reported elevated expression of cytotoxic mediators, perforin and granzyme B, in peripheral blood mononuclear cells (PBMCs) in response to M. tuberculosis antigen stimulation and elevated frequencies of cytotoxic cells expressing CD3 and Vα24 T-cell receptor in TB-IRIS patients compared to non-IRIS controls, suggesting that iNKT cells may play a role in TB-IRIS [24].