ERBB2 and cancer: This cancer was diagnosed as pT3N3M0 stage IIIC, luminal-HER2 (ER-positive, PgR-positive, HER2-positive, and Ki-67 index 35.6%), and she underwent chemotherapy with targeted therapy (docetaxel, cyclophosphamide, and trastuzumab), radiotherapy (to the chest wall and axillary region), and endocrine therapy (tamoxifen and leuprorelin) as adjuvant treatment.