MMP2 and acute respiratory distress syndrome: It has been described that during the acute phases of ARDS, MMP-2 and MMP-9 mediate the repair of the alveolar epithelial–endothelial space injury induced by mechanical ventilation (Lagente and others 2005; González-López and others 2011), and also their expression is promoted by hypoxia and high-volume mechanical ventilation (Foda and others 2001; Liu and Khalil 2017).