We utilized GSE25066, GSE20194, and GSE32646 cohorts, which included ER+/HER2− BC patients who underwent NAC: taxane and anthracycline in GSE25066, paclitaxel, 5-fluorouracil, cyclophosphamide, and doxorubicin in GSE20194, and paclitaxel followed by 5-fluorouracil, epirubicin, cyclophosphamide (P-FEC) combination in GSE32646. The gene discussed is ERBB2; the disease is breast cancer.