Demographics1.

1 Values shown are mean ± standard deviation unless otherwise noted.2 Data are shown for subjects who contributed samples for gene expression analysis.3 Data are shown for subjects who contributed samples for cilia length assessment.4 3rd–4th order airway epithelium obtained by bronchoscopic brushing.5 10th–12th order airway epithelium obtained by bronchoscopic brushing.6 Ethnicity is indicated as White (W), Black (B), Hispanic (H), Other (O).7 Spirometry values shown are pre-bronchodilator. FEV1 = forced expiratory volume in one second. FEV = forced vital capacity. TLC = total lung capacity. DLCO = diffusion capacity for carbon monoxide.8 The response to bronchodilator is shown as change in volume and % change for FEV1 and FVC for COPD subjects.9 The ratio of residual volume (RV) to total lung capacity (TLC) is shown as a % for COPD subjects.10 The DLCO adjusted for alveolar volume (VA) is shown as % predicted for COPD subjects.11 As defined by the Global Initiative for Obstructive Lung Disease criteria based on post-bronchodilator spirometry.12 The Modified Medical Research Council dyspnea score ranges from 0–4 with higher scores reflecting a greater degree of dyspnea.13 The St. George’s Respiratory Questionnaire measures the impact of COPD on overall health, daily life and well-being; scores range from 0–100 with higher scores = more limitations.14% Low attenuation area is defined as the % of lung volume with attenuation values ≤ −950 Hounsfield units on quantitative analysis of HRCT.*No CT data available for subjects in this group.