Used in cancer research, particularly for studying ferroptosis—a form of regulated cell death driven by iron and lipid peroxidation. It acts as a potent and selective inhibitor of system Xc−, a cystine/glutamate antiporter critical for maintaining cellular redox balance. By blocking cystine uptake, it depletes glutathione levels and inactivates glutathione peroxidase 4 (GPX4), leading to lethal accumulation of lipid reactive oxygen species in cancer cells. Its selectivity makes it a valuable tool for probing ferroptosis pathways and evaluating therapeutic strategies in tumors resistant to apoptosis, especially in glioblastoma and other solid cancers.