KDM5B and Epstein-Barr virus infection: Together with the KDM5B upregulation by BZLF1 observed in EBV-negative cells (Fig. 3b, c), these findings establish that BZLF1, an immediate early EBV lytic gene, directly stimulates KDM5B expression by binding to the ZREs within the KDM5B promoter, independent of EBV infection status.