ERBB2 and neoplasm: As previously described, the 909 tumours were classified into the following molecular subtypes: luminal A (ER+ and/or PR+, HER2−, Ki67 < 15%), luminal B (HER2−) (ER+ and/or PR+, HER2−, Ki67 ≥ 15%), luminal B (HER2+) (ER+ and/or PR+, HER2+), HER2 type (ER−, PR−, HER2+), five negative phenotype (5NP) (ER−, PR−, HER2-, cytokeratin 5 (CK5)−, epidermal growth factor receptor 1 (EGFR)−, and basal phenotype (BP) (ER−, PR−, HER2−, CK5+, and/or EGFR+)[21].