MTOR and glioblastoma: In glioblastoma and melanoma cells, diacylglycerol kinase α (DGKα), a lipid kinase converting diacylglycerol to phosphatidic acid, regulates both mTOR activity and MTOR mRNA levels via modulation of cyclic adenosine monophosphate (cAMP) (Fig. 1)12, 13.