Erastin is primarily used in cancer research due to its ability to induce a specific form of cell death called ferroptosis. It works by inhibiting system Xc⁻, a cystine-glutamate antiporter, leading to depletion of glutathione and accumulation of lipid reactive oxygen species. This mechanism is especially effective in killing cancer cells with high iron dependency or mutations in oncogenes like RAS. Researchers use erastin as a tool compound to study ferroptosis pathways and to screen potential anticancer agents that exploit oxidative stress. It also helps in understanding resistance mechanisms in tumor cells and supports the development of therapies targeting metabolic vulnerabilities in cancers.