ERBB2 and breast cancer: In 2013, Lips et al. studied in a cohort of 560 primary BC (51.3% ER+, 11.6% ER+/HER2+, 10% HER2+, and 27.1% TN) tumors treated with NAC and determined that a high histological grade (G3) was the best predictor of pCR in ER+/HER2− tumors (p < 0.004) [29].