In this study, for the first time we describe the anti-tumor efficacy of MHC class I HER2 peptide p66 and class II HER2 peptides (p5, p435, and p1209) pulsed DC1 vaccine alone or in combination with immune checkpoint blockade and HER2-targeted therapy in a preclinical model of HER2 over expressing breast cancer. This evidence concerns the gene ERBB2 and breast cancer.