Triple-negative breast cancer (TNBC), apart from the principle of genetic heterogeneity, lacks significant expression of these receptors (ER-/PR-/HER2-) and accounts for 10–20% of all BC cases, mostly among younger women [2,3], and a disproportionate 83% of deaths in comparison with other hormone receptor-positive or HER2-positive subtypes of BC irrespective of age and race [4]. This evidence concerns the gene ESR1 and breast cancer.