Doxorubicin, an anthracycline chemotherapy agent, has the ability to induce DNA double-strand breaks (DSBs) by inhibiting topoisomerase II and generating reactive oxygen species [47] and is commonly used as adjuvant treatment, particularly for triple-negative breast cancer (TNBC) and metastatic ER+ve cases. Here, ESR1 is linked to triple-negative breast carcinoma.