MMP-8 and MMP-9 are both known be elevated in early critical illness including ARDS and have been implicated in its pathogenesis through the destruction of components of the extracellular matrix.[13, 26, 27] In EARLI, both these markers were higher than the normal range described by the manufacturer of the assay (measured in healthy volunteers). This evidence concerns the gene MMP9 and acute respiratory distress syndrome.