Therefore, we determined whether the effect of UL23 on viral growth was PD-L1-dependent by adding an appropriate amount of PD-L1 blocking antibody to the culture medium and transfecting siR-PD-L1 into HFFs prior to infection with wild HCMV-Towne or HCMV-ΔUL23 and co-culturing with Jurkat cells. Here, CD274 is linked to infection.