In this study, we have constructed HER2/neu-based multi-epitope peptide vaccine for breast cancer consisting of GP2 (CTL epitope) and P4 (B-cell epitope) peptide that was covalently linked to KLH, as a source of Th cells stimulation and abbreviated as KLH–GP2–P4 (Figure 1). The gene discussed is GP2; the disease is breast carcinoma.