A recent study by Sundar et al. shows a significant reduction of REV-ERBα in small airway epithelial cells taken from patients with COPD, increased inflammatory responses in REV-ERBα knockout (KO) mice as compared to wild-type mice post cigarette smoke exposure, and a significant increase in pro-inflammatory cytokines in the KO. This evidence concerns the gene NR1D1 and chronic obstructive pulmonary disease.