GPX4 and fibrosarcoma: To this end, we induced ferroptosis in murine (NIH3T3 fibroblasts) and human (HT-1080 fibrosarcoma) transformed cell lines by incubating with the canonical ferroptosis inducers RSL3 (GPX4 inhibitor) [6, 10] or erastin (system xc− inhibitor) [7, 34].