RNA was isolated from bronchial brushings obtained from current and former smokers with and without COPD. mRNA expression was profiled using Affymetrix Human Gene 1.0 ST Arrays. RNA isolated from bronchial brushings was processed and hybridized to Affymetrix Human Gene 1.0 ST Arrays. A total of 269 arrays from 267 subjects were hybridized. Data from the 269 microarrays were used for RMA normalization. Data from 238 subjects was used in the analysis to determine the association of gene expression with COPD-related phenotypes.