In conclusion, our results demonstrate that metformin effectively inhibits TGF-β1-induced EMT-like process and cancer stem-like properties in GBM cells by targeting AKT/mTOR/ZEB1 signaling pathway in vitro. These results indicate a potential clinical use of metformin in treatment of GBM and provide supporting evidence to warrant further clinical trial for metformin as a safe and potent anticancer drug. Here, TGFB1 is linked to cancer.