These findings demonstrate that differential gene expression patterns between Gprc5a-knockout NNK-exposed MDA-F471 adenocarcinoma and normal lung cells may resemble lung tumor molecular profiles in other mouse models of lung carcinogenesis (e.g., urethane-exposed A/J mice, [30]) and in human lung adenocarcinomas. The gene discussed is GPRC5A; the disease is adenocarcinoma.