TGFB1 and breast cancer: Since TGF-β1 plays an important role in the enzalutamide-induced invasion and metastasis28 and metformin is capable of inhibiting TGF-β1 by activating AMPK in both breast cancer patients and mouse model,31 we decided to determine if metformin counteracts enzalutamide-induced EMT in prostate cancer by downregulating TGF-β1.