Epigenetic regulation of Nrf2 expression by hypermethylation at these sites has been seen in primary epithelial cells from patients with chronic obstructive pulmonary disease (COPD) who showed decreased Nrf2, increased reactive oxygen species, lipid peroxidation, and ferroptosis [4], demonstrating a role for this point of regulation in clinical medicine. This evidence concerns the gene NFE2L2 and chronic obstructive pulmonary disease.