Patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (EBC) who have a pathological complete response (pCR) after neoadjuvant HER2-targeted therapy in combination with chemotherapy have a lower risk of recurrence and death compared to patients with residual invasive disease at surgery [1,2,3,4,5,6,7]. This evidence concerns the gene ERBB2 and breast cancer.