GPX4 and neoplasm: For example, in the context of a B16-OVA tumor with OT-1 T cells, glutathione peroxidase 4 (GPX4) inhibition induced ferroptosis in CD8+ T cells while leaving tumor cells mostly unaffected, and this sensitivity was attributed to acyl-CoA synthetase long-chain family member 4 (ACSL4) (108), one of the key regulators of ferroptosis (109).