In a pooled analysis of four prospective neoadjuvant clinical trials that included 1098 patients with HER2-low and HER2-0 BC treated with combination chemotherapy, patients with HER2-low tumors had a significantly lower pathological complete response (pCR) rate than those with HER2-0 tumors did overall, including the HR+ subgroup. The gene discussed is ERBB2; the disease is breast cancer.