CCND1 and cytomegalovirus infection: In addition, to understand the reason behind enhanced G2-phase entry of WT-HCMV-infected cells, cyclin-D1 transcript level was measured in HCMV-infected HFFs after 2 dpi, as I-IFN inhibits cyclin-D1 expression to block cell cycle at G1-phase.36, 37, 38, 39, 40, 41, 42, 43, 44, 45 Interestingly, cyclin-D1 (ccnd1) expression was upregulated upon WT-HCMV infection compared with mock or ΔDUB-HCMV infection to HFFs (Supplementary Figure S2e), which inversely correlated with the I-IFN results observed in Figures 4a and b.