S100A9 and acute respiratory distress syndrome: Torre and colleagues found that S100 proteins interact with several key factors implicated in ALI/ARDS pathogenesis including TNF-а, IL-6 and p38MAPK, but has no obvious connections with other non-inflammatory proteins [28], suggesting that S100 proteins (mainly S100A8 and S100A9) could be a potential biomarker for ALI/ARDS prognosis and a therapeutic target in the settings of patients with ALI/ARDS.