C allele in EPHX T113C, G allele in GSTP1 A3313G, T allele in GSTP1 C341T, null in GSTM1/GSTT1, L allele in HO-1 affect the enzyme activity, meanwhile, these mutants could increase the COPD risk. The gene discussed is GSTP1; the disease is chronic obstructive pulmonary disease.