Endothelial dysfunction in COPD may be involved in the following aspects (65): (1) Toxic effects of cigarette smoke; (2) Production of autoantibodies in endothelial cells; (3) Vascular inflammation; (4) Increased levels of oxidative stress; (5) Antioxidant Pathway activation decreased; (6) NO release decreased, endothelin-1 expression increased and so on. The gene discussed is EDN1; the disease is endothelial dysfunction.