Preoperative (neoadjuvant) chemotherapy (NACT) is recommended for patients with locally advanced breast cancer (BC) of IIIA, IIIB, or IIIC stages and can be recommended for patients with IIA (T2N0 or T1N1) or IIB (T2N1 or T3N0) stages with triple-negative, luminal B, HER2-positive BC, and in cases with lymphogenous metastases1,2. The gene discussed is ERBB2; the disease is breast cancer.