This insight has been developed into a clinical framework that classifies breast cancer into five distinct types on a patient-to-patient basis, depending on the enrichment of HER2 and the expression of hormone receptors, as well as the triple-negative phenotype that shows no overexpression of HR receptors, which include estrogen and progesterone receptors, and lacks HER2 overexpression [7]. Here, ERBB2 is linked to breast carcinoma.