IFNA1 and infection: IPA analysis of these 24 genes showed only two pathways to be significantly enriched, “Activation of IRF by cytosolic PRRs” and “IFN signaling” (Table 2), neither of which features in cluster 2 from the microarray analysis of whole lung (Table 1) or in the 25 genes from the 96-gene panel that were induced more strongly (p < 0.05) in the lung at either 12 or 16 hours following x31 infection (Table 3).