Keeping T-he Killers at Bay via FcγRIIb.

Understanding how cytotoxic T cells are regulated is key for enhancing or suppressing their activity in tumor or transplantation settings. A study by Morris et al. (2020) in this issue of Immunity shows that crosslinking of inhibitory Fc receptor FcγRIIb by the suppressive cytokine Fgl2 limits cytotoxic CD8+ T cell responses by inducing T cell apoptosis.