IFNLR1 and infection: This equivalent mRV antigen burden in infected cells from Ifnlr1flox/flox and Ifnlr1 IEC-cKO mice in combination with the lack of correlation between antigen burden and percentage of infected cells suggests that the protective role of Ifnlr1 is to prevent infection of IECs rather than to limit replication within IECs after they are infected.