It has been demonstrated that immunotherapy-induced activated CD8+ T cells could downregulate the expression of two essential subunits of system XC−, SLC3A2, and SLC7A11, to inhibit the uptake of cystine via releasing interferon-gamma (IFN-γ), which promotes the accumulation of lipid peroxidation and consequent ferroptosis in cancer cells. This evidence concerns the gene CD8A and cancer.