PADI4 and infection: As shown in Supplementary Fig. 1c, HCMV infection led to a robust induction of the luciferase activity driven by either the PADI2 or PADI4 promoter (~7- and 3.5-fold, respectively), whereas UV-HCMV infection failed to induce a similar response, indicating that the synthesis of one or more viral proteins during the initial stage of infection is critical for transcriptional activation of PADI2 and 4 genes.