GPX4 and cancer: In 27HC-sensitive cancers, GPX4 levels decrease, whereas 27HC-resistant cancers maintain the mevalonate pathway, preserving GPX4 expression and activity, and increase xCT and lipid uptake through elevated lipid transporters (VLDLR, FABP4, CD36), thereby promoting tumor growth, EMT, and anti-LPO effects (Figure 3A).