HGF and infection: Furthermore, the concentrations of nine cytokines including IL-6, M-CSF, IL-1β, MIG which are monocyte/macrophage activation associated biomarkers (41), IFN-γ which is the sole type II IFN and important in early host defense against infection (50), IL-1α which activates the inflammatory process (51), IL-10 which regulates and suppresses the expression of proinflammatory cytokines (52), HGF, and IL-2Ra were significantly higher in HAdV-infected patients complicated with ARDS, and negatively correlated with the PaO2/FiO2 ratio (Figures 2, 3).