Plays a key role in the activation of the host resting B-cell and stimulation of B-cell proliferation. Acts by up-regulating the expression of viral EBNA1-6, LMP1, LMP2A and LMP2B genes, as well as several host genes including CD21, CD23 and MYC. Activates transcription by acting as an adapter molecule that binds to cellular sequence-specific DNA-binding proteins such as host CBF1, SMARCB1 and SPI1. Once EBNA2 is near promoter sites, its acidic activating domain recruits basal and activation-associated transcription factors TFIIB, TAF40, TFIIH components ERCC2 and ERCC3, and CBP in order to promote transcription. Alternatively, EBNA2 can affect activities of cell cycle regulators and retard cell cycle progression at G2/M phase. It also induces chromosomal instability, by disrupting mitotic checkpoints, multi-nucleation and formation of micronuclei in infected cells.