GPX4 and glioma: The five glioma cell lines assayed had baseline sensitivity to ferroptosis by the GPX4 inhibitor RSL3 (Fig. 1a), confirmed by live-cell confocal microscopy showing RSL3 mediated induction of lipid peroxidation as evidenced by green fluorescence shift in the Bodipy-C11 dye following addition of RSL3 (Supplementary Fig. 1a).