GPX4 and neoplasm: For example, CD8+ T cells can secret IFN‐γ, which down‐regulates the expression of SLC3A2 and SLC7A11 on tumor surface, thereby reducing the intracellular uptake of cystine, and ultimately leading to ferroptosis.[12] Knockout of glutathione peroxide 4 (GPX4) in B1 and marginal‐zone (MZ) B cells can trigger their ferroptosis by inducing lipid peroxidation, thus affecting host immune response.[20] However, knocking out GPX4 in follicular B cells (FOB) doesn't cause ferroptosis.