MMP8 and idiopathic pulmonary fibrosis: The percentage of neutrophils that stain positively for surface MMP-8 (which increases when neutrophils are activated [12], [17]) is also similar in IPF patients and controls (17.8± SEM 5.6%; n = 32 versus 3.4±1.9%; n = 5, respectively; p = 0.79).