Treatment of EBV+ tumor cells-inoculated mice with rBCG::hGM-CSF-BZLF1 significantly delayed tumor formation and prolonged mouse survival compared to treatment with pBCG, rBCG::hGM-CSF or rBCG::BLZF1, most likely through the induction of cytotoxic T lymphocytes. This evidence concerns the gene BLZF1 and neoplasm.