Prostaglandin-endoperoxide synthase 2 (PTGS2) expression, which encodes cyclooxygenase-2 (COX-2), is prominently upregulated during piperazine erastin-induced ferroptosis (Yang et al., 2014), Targeted disruption of GPX4 in mouse skin in vivo (Sengupta et al., 2013) as well as GPX4 knock-down or its inhibition by RSL3 in tumor cells in vitro also induce robust PTGS2 expression (Seiler et al., 2008; Yang et al., 2014). This evidence concerns the gene PTGS2 and neoplasm.