The expression levels of mRNA encoding IFN-β and other ISGs were significantly lower in DP71L-transfected PK-15 and DP71L stably expressing 3D4/21 cells than in control cells (Figures 2C and D), suggesting that ASFV DP71L negatively regulates the IFN-I signaling pathway and expression of antiviral genes in response to infection with viral DNA. Here, IFNB1 is linked to infection.