To assess the effects of simultaneous MEK and PI3K/mTOR inhibition on the MAPK and PI3K/mTOR signaling cascades and to integrate these data with the phenotypic data of the radiation response after simultaneous MEK and PI3K/mTOR inhibition, we treated glioblastoma SNB19 and lung carcinoma A549 cells with AZD6244 and NVP-BEZ235 alone and in combination. This evidence concerns the gene MTOR and glioblastoma.