POR and cancer: Regarding the enzymes that drive lipid peroxidation, while lipid peroxidation was initially proposed to be mediated by lipoxygenases (ALOXs) (Yang et al., 2016), the role of ALOXs in lipid peroxidation was subsequently challenged (Shah et al., 2018), and more recent studies revealed that, at least in most cancer cell lines, cytochrome P450 oxidoreductase (POR) appears to play a more dominant role in mediating lipid peroxidation (Yan et al., 2020; Zou et al., 2020b) (Fig. 1).