NFE2L2 and chronic obstructive pulmonary disease: Therefore, we investigated the protective role of crocin against cigarette smoke exposure (CSE)-mediated oxidative stress and the inflammatory process in COPD, modifications of Nrf2 and its upstream regulator genes (PKC, PI3K AND MAPK) and also GCLc and GSH as downstream enzymes controlled by Nrf2 and impairment of cardiac hemodynamics and remodeling in rats with COPD.