Therapeutic choices are usually based on traditional histopathological features, with the recognition in the clinical practice of four main subtypes of BC with predictive and prognostic value: luminal A-like, luminal B-like (human epidermal growth factor receptor 2 (HER2)-negative), HER2-positive (HER2+), and triple-negative BC (TNBC) [1]. This evidence concerns the gene ERBB2 and breast cancer.