GPX4 and chronic obstructive pulmonary disease: Yoshida et al. (2019) reported that accumulation of unstable iron and enhanced lipid peroxidation occurred in cells exposed to CS, and that the accumulation of iron was more severe after GPX4 was knocked out, indicating that ferroptosis may participate in the process of COPD. Furthermore, particle matter 2.5 (PM 2.5) has been shown to induce ferroptosis; the mechanism may be closely related to iron overload, lipid peroxidation, and redox imbalance (Ren et al., 2021).