MMP9 and injury: Since the NF-κB element is believed to be the main regulator of CINC, MMP-9 and iNOS expression, and MAP kinase pathways have been demonstrated to contribute to the activation of NF-κB [15,44,45], we attempted to investigate the action of MAP kinases on the upstream of NF-κB signal transduction pathways in LPS-induced acute lung injury.