In contrast, other studies have reported that NFE2L2 mRNA expression was reduced in alveolar macrophages and bronchial epithelium from mild COPD patients compared to controls (Suzuki et al. 2008) and Nrf2 protein and mRNA expression were reduced in alveolar macrophages from severe COPD patients (Goven et al. 2008; Fratta Pasini et al. 2020). Here, NFE2L2 is linked to chronic obstructive pulmonary disease.