MTOR and glioblastoma: This enhanced cell cycle arrest in the SNB19 cell line after combined MEK and PI3K/mTOR inhibition, indicates an additive or synergistic anti-proliferative effect of AZD6244 and NVP-BEZ235, which has not been shown for glioblastoma cell lines yet, indicating a therapeutically relevant potential of combining these two inhibitors in this tumor entity.