To investigate whether the imbalance of oxidant/antioxidants is involved in the development of COPD, contents of oxidants (MDA, lipid hydroperoxide) and antioxidants enzymes (SOD) were evaluated in sera of patients with COPD and non-COPD, and HPASMCs exposed to TGFβ1. The gene discussed is SOD1; the disease is chronic obstructive pulmonary disease.