Moreover, phage-based HER2 vaccines delay the onset of mammary tumors, reduce tumor growth and multiplicity, and produce anti-HER2 antibodies that decrease cell viability, providing a promising alternative strategy for the treatment of HER2-positive breast cancer using both trastuzumab-sensitive and trastuzumab-resistant BT-474 cells [181]. This evidence concerns the gene ERBB2 and neoplasm.