Therefore, we also assessed the association between the CYP2A6 locus and chronic obstructive pulmonary disease (COPD; 982 cases and 4,480 controls), lung cancer (997 cases and 6,491 controls) and arteriosclerosis obliterans (ASO; 499 cases and 10,975 controls) in our GWAS and replication sample sets. Here, CYP2A6 is linked to chronic obstructive pulmonary disease.