Others have reported the inhibition of IFN-α in porcine peripheral blood mononuclear cells (PBMCs) [70,71] and the inhibition of type I IFN (IFN-α /IFN-β) in PK-15 cells [72,73] following PCV2 infection or in the presence of PCV2 viral protein or DNA. This evidence concerns the gene IFNB1 and infection.