GPX4-IN-18 (Compound 17) is a ferrocene-containing inhibitor of glutathione peroxidase 4 (GPX4), and it also acts as a ferroptosis inducer. It enhances the production of reactive oxygen species (ROS) and malondialdehyde (MDA) levels in OS-RC-2 clear cell renal carcinoma cells. In HT-1080 cells, GPX4-IN-18 induces ferroptosis with IC50 values of 0.007 µM (without iron inhibitor-1) and 1.486 µM (with iron inhibitor-1). Additionally, GPX4-IN-18 reduces tumor volume and intratumoral GPX4 levels in an OS-RC-2 xenograft mouse model.