KEAP1 and chronic obstructive pulmonary disease: As previous studies have reported conflicting NFE2L2 gene expression data in COPD compared to controls (Fratta Pasini et al. 2016, 2020; Goven et al. 2008; Suzuki et al. 2008), we conducted protein expression studies for Nrf2 and Keap-1 in alveolar macrophages and the bronchial epithelium, using lung tissue from COPD patients compared to control non-smokers (NS) and smokers (S).