The FBXW7-deficient peritoneal macrophages expressed downregulated IFN-β and IFN-α4 mRNA upon infection with VSV, H1N1 virus or RSV (Fig. 2a) and this phenomenon was also found in bone marrow-derived DCs (BMDCs; Fig. 2b) and bone marrow-derived macrophages (BMDMs; Supplementary Fig. 3a). Here, IFNA4 is linked to infection.