NFE2L2 and chronic obstructive pulmonary disease: The Nrf2 related antioxidant system was impaired in tobacco smoke-induced COPD mice model and PM-induced COPD model, also activation of Nrf2 attenuated COPD and emphysema caused by cigarette smoke exposure (Sussan et al., 2009; Han et al., 2011; Zhang K. et al., 2018).