IFNB1 and infection: However, no significant induction of type I IFNs was observed when the viruses were used to infect ΔIRF7 cells (Fig 7C and 7D) We also measured IFN secretion following infection of tHF and ΔIRF7 cells with WT and miR-UL22A mutant viruses (Fig 7E–7H) and showed enhanced secretion of IFNβ and IFNα upon ΔmiR-UL22A mutant virus infection that is reduced in tHF cells infected with ΔmiR-UL22A/SMAD3shRNA virus and absent in ΔIRF7 cells.