IFITM3 and infection: In addition to upregulating more ISGs than other epithelial cell types, the highest upregulated ISG in ΔPB1-Cre-infected ciliated cells is Ifitm3. IFITM3 is known to inhibit entry/uncoating of IAV [48, 49]; the potent upregulation of Ifitm3 during early stages of infection and/or the rapid upregulation of ISGs could explain our previously described protection of ciliated cells during virus spread [14].