Clinically, breast tumors are categorized into three primary groups based on the presence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2): ER-positive (ER+), HER2-positive (HER2+), and triple-negative breast cancer (TNBC) [2]. The gene discussed is PGR; the disease is breast neoplasm.