The current preoperative NAC regimen for breast cancer is based on factors such as molecular classification and predominantly comprises a 6-cycle TEC or 8-cycle EC-T regimen, that is, taxane combined with anthracycline, For patients with HER-2-positive breast cancer, targeted drugs are often added, such as trastuzumab and pertuzumab. The gene discussed is ERBB2; the disease is breast cancer.