It is assumed that the favorable influence of progestins is predominantly associated with their own cytotoxic effects on some hormone-dependent tumors (breast cancer, endometrial cancer, cervical cancer); the modulation of expression and activity of MDR-related proteins; the inhibition of survival signaling pathways, especially TGF-β and Wnt/β-catenin pathways which activate the proliferation and promote MDR in cancer cells; and the triggering of mitochondrial-dependent apoptosis. Here, TGFB1 is linked to breast cancer.