CCL2 and acute respiratory distress syndrome: Cytokine storm refers that, based on the microbial infection, body fluids of patients generate massive cytokines rapidly, such as TNF-α, IL-1, IL-6, IL-12, Interferon-α (IFN-α), IFN-β, IFN-γ, monocyte chemotactic protein-1 (MCP-1) and IL-8, resulting in the acute respiratory distress syndrome and multiple-organ dysfunction syndrome (7, 8).