HDAC1 and acute respiratory distress syndrome: At the single gene level, nine genes were associated with ARDS mortality through a systems biology approach including HDAC1, encoding a histone deacetylase (HDAC) previously linked to acute inflammatory disorders11–13 including acute lung injury with HDAC inhibitors shown to prevent endothelial hyperpermeability14, the major pathophysiological defect in acute lung injury15–17.