NFKB1 and viral infectious disease: Since previous work has reported the HBV X protein could stimulate transcription from a variety of promoter elements, including NF-κB [31], together with our observation that HBeAg also has an inhibitory effect to NF-κB, it is assumed that HBV Pol, E and X may regulate NF-κB activity coordinately at different stages during virus infection (see discussion).