Collectively, compared with U-IHNV, J-IHNV infection caused down-regulation of the dusp4, gadd45α, plk2, and ccn2 genes in a similar manner to EBV, HCV, aMPV/C, and PRRSV, suggesting that these genes may perform the same role during different virus infections, but the exact role within IHNV remains to be clarified. This evidence concerns the gene CCN2 and viral infectious disease.