GSTP1 and chronic obstructive pulmonary disease: For example, although many studies did not find the association between EPHX1 and the susceptibility to COPD or disease severity [5, 6], Vibhuti et al. [7] approved that and the combination of 113H/139H alleles of mEPHX and 105V/114V alleles of GSTP1 genotypes with same alleles is associated with imbalanced oxidative stress and lung function in COPD patients.