TGFB1 and infection: To characterize the viral gene product requirements for TGF-β1 activation by HCMV infected epithelial cells after EMT, viral polymerase inhibitors ganciclovir (GCV) and foscarnet (PFA) were added at a range of concentrations to inhibit viral replication, one hour after HCMV TR infection but before raTGF-β1 stimulation, and again after washing, and the luciferase bioassay for TGF-β1 performed (Figure 6A, left panel).