NFKB1 and Epstein-Barr virus infection: Also, the hypomethylation in B cells took place after 24-h post EBV infection, when proliferation started, and many of the hypomethylated domains associated with B cell activation are enriched with Pol II and a NFκB subunit p65 (69), suggesting EBV-associated demethylation induces B cell activation genes through NFκB activity.