A remarkable study was conducted by Wang W. et al. (2019), who reported that CD8+ T cells enhance ferroptosis by down-regulating SLC3A2 and SLC7A11, and the induction of ferroptosis contributes to the anti-tumor efficacy of immunotherapy, suggesting that the immune system might, at least in part, function through ferroptosis (Stockwell and Jiang, 2019). The gene discussed is CD8A; the disease is neoplasm.