PGR and triple-negative breast carcinoma: The immovableness of MDA-MB-231 cells could be due to their receptor composition, the negative expression of ER, PR and HER2 [16], in line with the notion that triple negative breast cancer cells respond differently to Notch, Hedgehog, Wnt/β-catenin and TGFβ signaling pathways [44], which are activated by ASCs [45, 46].