Recent expression profile analyses revealed that lung adenocarcinomas canbe divided into several subgroups with diverse pathological features. Because cellular heterogeneity of tumors can confound these analyses, we used laser capture microdissection and microarray expression analysis to characterize the molecular profiles of lung adenocarcinomas. We found 45 genes delineating smokers and nonsmokers that were located at chromosomal loci frequently altered in non-small cell lung cancers, and 27 genes, which were differentially expressed between survivors and nonsurvivors 5 years after surgery. These results are consistent with the hypothesis that the abnormal expression of genes involved in maintaining the mitotic spindle checkpoint and genomic stability, e.g., hBUB3, hZW10, and APC2, contribute to the molecular pathogenesis and tumor progression of tobacco smoke-induced adenocarcinoma of the lung.