Surgery, radiotherapy, chemotherapy, and molecular targeted therapies are currently used for breast cancer treatment; however, effective therapies for patients diagnosed with triple-negative breast cancer [TNBC; i.e., those that are negative for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)] remain limited (2–4). This evidence concerns the gene PGR and breast cancer.