SMAD3 and cytomegalovirus infection: In order to assess the role of miR-UL22A regulation of SMAD3 and IRF7-mediated signaling in the context of HCMV infection, we next tested the induction of IFN transcripts following infection with WT and ΔmiR-UL22A mutant viruses in tHF and ΔIRF7 cells.