PCSK1 and fibrosarcoma: First, MPP+-induced cell death, but not ferroptosis, was inhibited by Nec-1, while we confirmed that Nec-1 did not inhibit either ferroptosis (death) or accompanying lipid peroxidation induced by erastin or RSL3 in HT1080 cells (a human fibrosarcoma cell line) and mouse embryonic fibroblasts (MEFs) (Supplementary Figures 5A–D).