A previous study reported that upregulation of glutathione peroxidase 4 (GPX4), a key negative regulator of ferroptosis, and downregulation of heme oxygenase-1 (HMOX1), which promotes ferroptosis by increasing the labile iron pool (LIP), were poor prognostic factors in ESCC (Shishido et al., 2020). Here, GPX4 is linked to esophageal squamous cell carcinoma.