Notably, multiple antiviral proteins were also dramatically decreased in PAMs during the PRRSV-ADE infection, including ISG15, ISG20, IFIT1 (ISG56), IFIT2 (ISG54), IFIT3 (ISG60), IFIT5 (ISG58), OAS1, Mx1, RSAD2, TRIM22, TRIM25 and TRIM34, except for TRIM52. This evidence concerns the gene ISG20 and infection.