ERBB2 and breast cancer: Gallen Consensus 2011 [3] is, to date, the classification system used to categorize BC based on its molecular subtypes according to the Luminal A (ER+ /PR+ /HER2−/lowKi-67); Luminal B (ER+ /PR+ /HER2−/+ /high Ki-67); HER2+ (ER-/PR-/HER2+) and Triple-negative breast cancers/TNBCs (ER−/PR−/HER2−) [4].