Neoadjuvant chemotherapy results in equivalent outcomes to adjuvant chemotherapy in patients with operable/locally advanced breast cancer and has emerged as a standard practice for most patients with triple negative breast cancer (TNBC), human epidermal growth factor receptor 2 (HER-2) positive breast cancer, and in select patients with the hormone-receptor positive (HR+)/HER2 negative (HER2-) phenotype. The gene discussed is ERBB2; the disease is breast cancer.