CCL2 and infection: To further understand the cell reactions triggered by pdmH1N1 or H7N9 infection, we also used a Bio-Plex Cytokine panel to investigate the concentrations of 27 target cytokines, each of which was classified to one of the following five groups: chemokines (IL-8, IP-10, RANTES, MIP-1β, eotaxin, MCP-1, and MIP-1α), growth factors (PDGF-BB, FGF basic, GM-CSF, VEGF, and G-CSF), proinflammatory cytokines (IL-1β, IL-6, and TNF-α), T-helper cytokines (IL-12, IL-2, IL-5, IL-9, IL-17, IFN-γ, IL-10, IL-4, and Il-13), and others (IL-1Ra, Il-7, and IL-15) (Table 3).