As shown in Table 1 at 4 hpi, seven out of the top ten PR/8 upregulated genes were type I IFN family members, and another two up-regulated genes, IFN-stimulated gene (ISG) 20 and CXCL11, were IFN-stimulated genes [24] . At 24 hpi, IFN-stimulated genes CXCL9-11, and IFITM1 were among the top ten genes upregulated by PR/8 (Table 2) . Therefore, we verified the microarray data with a focus on IFN-associated genes by real-time RT-PCR ( Figure 1 ). As shown in Figure 1A , PR/8 infection induces an early response in type I IFN genes IFNA1 and IFNB as well as type III IFN genes IL-29 and IL-28A, although the degree of increase was slightly less than that of most type I IFN genes (Tables 1 and 2) . Along with the increased IFN gene expression, the infection also increased expression of well-known PRR genes associated with IFN production. mRNA levels of RIG-I and melanoma differentiation associated protein-5 (MDA-5) were mainly increased at 4 hpi, whereas TLR3 and 7 were mainly stimulated at 24 hpi ( Figure 1B ). The infection also significantly increased mRNA of IFN-stimulated anti-viral genes myxovirus (influenza virus) resistance 1 (MX1), 2959 oligoadenylate synthase (OAS), and IFN-stimulated gene 56 (ISG56) ( Figure 1C and Data S1), as compared to control cells.