RB1 and infection: At the protein expression level (day 3 post-infection), Rb was diminished whereas pRb was highly expressed in HMEC-HCMV-DB (p-value(HCMV-DB: HMEC-UI) = 0.04) and to a lesser extent in HMEC-HCMV-TB40/E (p-value(HCMV-TB40/E: HMEC-UI) = 0.04, p-value(HCMV-TB40/E: HCMV-DB) = 0.8) (Figures 6A, B).