A differential time-kinetic dependent expression of cytokines and chemokines with acute response cytokines TNFα and IL-1β and chemokines IL-8 and MCP-1 in the early minutes to hours after infection, followed by a more sustained increase in IL-6 was demonstrated by microarray-based transcriptional changes in H5N1 and 1918 H1N1 in comparison to seasonal H1N1 virus infection, with transcriptional changes in the NF-kB pathway central in the cytokine storm (34). Here, IL6 is linked to infection.