Compared to other types of breast cancer, triple-negative breast cancer (TNBC) has limited therapeutic avenues, but it is extremely aggressive due to the lack of expression of human epidermal growth factor receptor-2 (HER2), progesterone receptor (PR) and oestrogen receptor (ER), often leading to a poor prognosis [62]. The gene discussed is PGR; the disease is triple-negative breast carcinoma.