ESR1 and triple-negative breast carcinoma: Triple-negative breast cancers (TNBCs), characterized by a combined estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor 2 (HER2)-negative immunophenotype, make up 12–17% of the entire malignant breast population and show an epidemiological connection to younger women, African American race, and breast cancer gene 1 (BRCA1) mutations; most fall into the BLBC subtype [10,11,12].