BZLF1 (BamHI Z fragment leftward open reading frame 1), also known as Zta, EB1, is an immediate-early viral gene of the Epstein–Barr virus (EBV) of the Herpes Virus Family, which induces cancers and infects primarily the B-cells of 95% of the human population.[1] This gene (along with others) produces the expression of other EBV genes in other stages of disease progression, and is involved in converting the virus from the latent to the lytic form.