The analysis of 8 gene fragments of A/Swine/Fujian/F1/2010 (H1N2) strain showed that the HA, NP, M, and NS gene fragments were originated from classical pig influenza H3N2 subtype, NA and PB1 were derived from human swine influenza H3N2 subtype, and PB2 and PA gene were from avian influenza virus, as shown in Figure 9. Here, XK is linked to influenza.