Moreover, it has been reported that cell surface protein‐CD63‐positive BCs have higher invasive ability and are resistant to chemotherapy.[55] These findings collectively highlight the therapeutic potential of a neutralizing monoclonal antibody against CD63, as the antibody could not only successfully eradicate CD63+ CAFs and thus improve tamoxifen efficacy in tumor‐bearing mice but also suppress breast cancer metastasis and improve the therapeutic effect of chemotherapy by eradicating cell surface protein‐CD63‐positive BCs. Here, CD63 is linked to neoplasm.