Both animal and clinical studies have demonstrated that the inflammatory response of asthma exacerbations is featured by the infiltration of a mixture of multiple immune cells including eosinophils and neutrophils, and is strongly linked to many proinflammatory cytokines and chemokines including type 1 and 2 cytokines, tumor necrosis factor (TNF)-α, MCP-1 and IL-6 (3, 4). Here, CCL2 is linked to asthma.