PGR and triple-negative breast carcinoma: Taking into account that the chemotherapeutic agents are the only therapeutic option for patients with triple-negative breast cancer due to the lack of specific molecular targets (e.g., expression of HER2-neu, or estrogen/progesterone receptors), we focused primarily on the triple-negative breast cancer (TNBC) cell lines (e.g., HCC1806 and MDA-MB-231).