Serum MMP-1 (p < 0.01), MMP-2 (p = 0.03), MMP-7 (p < 0.01), MMP-8 (p = 0.01), MMP-10 (p < 0.01), and MMP-12 (p < 0.01) concentrations were significantly elevated in patients with IPF compared with controls, whereas serum MMP-2 (p < 0.01), MMP-7 (p < 0.01), MMP-9 (p = 0.03), MMP-10 (p < 0.01), MMP-12 (p = 0.01) concentrations were significantly elevated in patients with IPF compared with COPD patients. The gene discussed is MMP9; the disease is idiopathic pulmonary fibrosis.