NFE2L2 and pulmonary emphysema: Thus, Nrf2-deficient mice exhibit more susceptibility to airway inflammation and emphysema after DEP inhalation and cigarette smoke, respectively [18–20]; moreover, Nrf2-deficient dendritic cells exposed to PM secrete more pro-inflammatory mediators than the wild-type cells [21], strongly suggesting a protective health effect of Nrf2 against air pollutants.