Compared with WT BMDM, TRIM18 KO BMDM produced 2- to threefold more IFN-α and IFN-β proteins (Fig. 2c, d) and twofold more mRNAs of ISG15 and ISG56 (Additional file 2: Fig. S5c, d) post-infection by RNA viruses Flu PR8 and CVB3. This evidence concerns the gene ISG15 and infection.