IFNA1 and infection: As shown in Figure 13a and Figure 14a, both the IFN-α mRNA level in PRRSV-infected cells pretreated with anti-FcγRI IgG or anti-FcγRIII IgG and its protein level in culture supernatants of PRRSV-infected cells pretreated with anti-FcγRI IgG or anti-FcγRIII IgG were significantly downregulated at any time point post-infection, compared to PRRSV-infected-cells pretreated with RNI.