These biomarkers help to identify the triple-negative breast cancer (TNBC) lacking the expression of ER, PR, and HER2 which is the most aggressive type of breast cancer associated with poor prognosis and limited treatment options, thus improving the management and treatment options with the ultimate goal of improving clinical outcomes.52 Moreover, identifying curative predictive biomarkers to distinguish patients who are most likely to respond to anticancer therapy from all cancer patients enhances therapeutic efficiency, decreases treatment costs, and avoids adverse events. Here, ESR1 is linked to breast cancer.