Breast cancers are classified, inter alia, based on the expression of receptors such as estrogen receptor α (ERα; often referred to as ER), progesterone receptor (PR), and human epidermal growth factor receptor (EGFR; also known as ErbB2/HER2) with tyrosine kinase activity [3,4,5,6]. This evidence concerns the gene ESR1 and breast carcinoma.