PF4 and infection: Genes up-regulated early in infection were functionally associated with immune responses including several interferon-inducible genes such as Irf7, Oas2, Ifit3 and Ifit2. Genes up-regulated in the spleen later in infection were associated with wound healing and defence responses as well as chemotaxis (e.g. CXCL4, CCL8, S100A8), glycolysis and peroxidase activity.