Another study of 355 COPD cases and 195 apparently healthy (ex)smoking controls failed to find an association between the GSTOs’ polymorphisms and FEV1 but found that the GSTO2 N142D polymorphism and the GSTO1 140D/GSTO2 142D haplotype are associated with an increased risk of COPD [86]. Here, GSTO1 is linked to chronic obstructive pulmonary disease.