GPX4 and cancer: Ferroptosis was originally discovered by a small molecule screen to identify a potential anti-cancer drug that could specifically induce cell death in rat sarcoma virus (RAS) mutant cancer cells, which led to the identification of various ferroptosis inducers, including RAS-selective lethal 1 (RSL1: Erastin) and RSL3 [1, 2]; Erastin depletes intracellular GSH by blocking cystine incorporation via SLC7A11, while RSL3 directly binds to GPX4 and inhibits its activity.