RSL3 is widely used in scientific research as a potent and selective inducer of ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation. It is particularly valuable in cancer research due to its ability to kill cancer cells that are resistant to other forms of cell death, such as apoptosis. RSL3 works by directly inhibiting glutathione peroxidase 4 (GPX4), a key enzyme that protects cells from oxidative damage. This inhibition leads to the accumulation of lethal lipid reactive oxygen species, triggering ferroptosis. Researchers use RSL3 to study the molecular mechanisms of ferroptosis and to identify vulnerabilities in tumor cells, especially in cancers with mutations in the RAS pathway or those exhibiting high levels of oxidative stress. It is also employed in screening for new compounds that modulate ferroptosis, helping to develop potential anticancer therapies. Due to its specificity, RSL3 serves as a critical tool compound in validating GPX4 as a therapeutic target and in exploring the role of redox balance in disease.