Two of the identified proteins, matrix metalloprotease 13 (MMP13) and thioredoxin-like 2, were confirmed to be increased in COPD subjects with Western Blot and immunohistochemical staining, with MMP13 localized to the alveolar macrophage and type II pneumocytes and thioredoxin-like 2 found in the bronchial epithelium. The gene discussed is MMP13; the disease is chronic obstructive pulmonary disease.