GPX4 and glioma: Cysteine and methionine deprivation was found to synergize with the GPX4 (glutathione peroxidase 4) inhibitor RSL3 to increase the number of iron-dead cells and lipid peroxidation in mouse and human glioma lines, and a reduced cysteine- and methionine-restricted diet improved the response of mice to RSL3 treatment and prolonged survival (61).