Although there were differences in induction of some ISGs (IFITM3, IRF3, ISG15, VIG1, and MX1), mRNA levels of type I IFNs were below the detection limit in pLNs or similar in spleens of B6 and CD169−/− mice post-FVC infection (Figures S4A–S4D). Here, ISG15 is linked to infection.