Specifically, it has been consistently shown that structural proteins such as actin and myosin heavy chain (MyHC) [19,23], and enzymes such as creatine kinase and carbonic anhydrase-3 undergo severe oxidation within the respiratory and limb muscles of patients with COPD, both at rest and after exercise [15,16,17,19,23,141]. Here, MYH6 is linked to chronic obstructive pulmonary disease.