Human Epidermal Growth Factor Receptor 2-positive (HER2+) breast cancer (BC) accounts for 15–30% of all BC subtypes and is recognized as a more aggressive pathology compared to Hormone Receptor-positive (HR+)/HER2-negative (HER2−) BC, with HER2+ BC patients having a poorer prognosis [1,2]. This evidence concerns the gene HR and breast carcinoma.