A key to solving these problems would be a more effective therapeutic method for treating triple-negative breast cancer (TNBC), the most metastatic and resistant type of breast cancer named for its complete deficiency in oestrogen receptor (ER), progesterone receptor (PR) plus human epidermal growth factor receptor 2 (HER2) in tumour cell surface.5–8. This evidence concerns the gene PGR and breast carcinoma.