MMP8 and chronic obstructive pulmonary disease: With its unique characteristics, MMP8 has been shown to play an important role in the pathogenesis of respiratory diseases such as acute respiratory distress syndrome or acute lung injury (Fligiel et al., 2006), COPD (Vernooy et al., 2004), interstitial lung disease (Choi et al., 2002), and hospital-acquired pneumonia (Schaaf et al., 2008).