MTOR and central nervous system cancer: It has been demonstrated that the (−)gossypol enantiomer (AT101) significantly increases cell death by mitochondrial dysfunction and autophagy induction in apoptosis-resistant human glioma cell lines; cell death was inhibited by a knockdown of pro-autophagic proteins like Beclin-1 and Atg5, and it was increased by a mTOR knockdown [308].