Treatment for TNBC [tumors that are estrogen receptor (ER)-negative, progesterone receptor (PR)-negative and human epidermal growth factor receptor 2 (HER2) non-amplified] continues to be a challenge due to the fact that it is, by definition, insensitive to the hormonal therapies and trastuzumab that have been developed to treat other types of breast cancer. The gene discussed is PGR; the disease is breast carcinoma.