Triple-negative breast cancer (TNBC), defined as estrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative, is the most lethal subtype of breast cancer due to its highly-aggressive characteristics, heterogeneity, and the availability of few treatment methods [3,4]. The gene discussed is PGR; the disease is breast carcinoma.