Moreover, Nordin et al. integrated the cytotoxic T cell (GP2) and B cell (P4) peptide epitopes of HER2/neu to prepare a peptide vaccine and observed that compared with vaccination with GP2, a stronger preventive and therapeutic effect against HER2-positive breast cancer was achieved due to the production of neutralizing antibodies (Nordin et al., 2021). Here, GP2 is linked to breast cancer.