Being a multifaceted disease, BrCa can be classified into various subclasses based on the expression status of estrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor 2 (HER2) and antigen ki-67 (Ki-67), which suggest different therapeutic guidance and prognostic implications for BrCa patients [2]. This evidence concerns the gene ESR1 and invasive breast carcinoma.