Barreiro et al. assessed the levels of protein oxidation, lipid peroxidation, catalase and Mn-SOD expressions, nitric oxide synthases, and protein tyrosine nitration in quadriceps muscles of patients with patients with COPD, finding development of both oxidative and nitrosative stresses in the quadriceps of patients with COPD, suggesting their involvement in muscle dysfunction [200]. Here, SOD2 is linked to chronic obstructive pulmonary disease.