Immunohistochemistry analysis of ECM proteins from lung specimens of patients with COPD has shown that abundant elastin can be detected during the early stages of COPD and that the abundance of collagen is correlated with the degree of intimal thickness, suggesting that collagen deposition has important consequences for pulmonary vascular remodeling associated with COPD (60, 63–65). Here, ELN is linked to chronic obstructive pulmonary disease.