Moreover, comparing the effects of metformin with a “pure” AMPK activator, the peptide A769662, which was unable to inhibit mTOR and GBM cell proliferation, it was shown that metformin suppresses GBM proliferation enhancing PRAS40–RAPTOR association to inhibit mTOR, independently of AMPK (217). This evidence concerns the gene AKT1S1 and glioblastoma.