Interestingly, our work shows that metformin induces decreased proliferation, cell cycle arrest, autophagy, and apoptotic cell death in vitro in part via AMPK and Redd1 activation and inhibition of mTOR pathways, but differentially affects glioma cell growth depending on the genetic and mutational backgrounds, particularly their PTEN status. The gene discussed is MTOR; the disease is central nervous system cancer.