The BC subtype guides the standard systemic therapy administered, which consists of endocrine therapy (tamoxifen [12,13,14], letrozole [15,16,17,18], anastrozole [19], exemestane [20,21]) for all HR+ tumors, trastuzumab-based ERBB2-directed antibody therapy plus chemotherapy for all ERBB2+ tumors [9] (such cyclophosphamide [22,23], paclitaxel [22,24,25], docetaxel [24], carboplatin [26,27,28]), and classical chemotherapy alone for triple-negative breast cancer (capecitabine [29,30,31], eribulin [32,33], vinorelbine [34,35], gemcitabine [36,37], talazoparib [38]). Here, ERBB2 is linked to breast cancer.