They demonstrate that (1) the therapeutic effect of HER2/neu antibody is tumor-specific T-cell dependent; (2) effective anti-HER2/neu treatment achieves immune memory that resists the subsequent high dose tumor rechallenge; (3) anti-HER2/neu treatment results in enhanced CD8+ cell infiltration in the tumor tissue of mouse models and clinical patients. This evidence concerns the gene ERBB2 and neoplasm.