The expression levels of tumor necrosis factor-alpha (TNF-α), IL-4, IL-10 and interferon-γ (IFN-γ) in MH-SCD163 and RAW264.7CD163 cells after PRRSV infection at 24 hpi and 48 hpi were measured and the results are shown in Fig. 4a (JXA1 infection) and Fig. 4b (VR-2332 infection). The gene discussed is IL4; the disease is infection.