MTOR and meningioma: Previously, we have found that several of these pathways such as the MAPK kinase kinase-MAPK kinase-mitogen activated protein kinase (Raf-1-MEK-1-MAPK) pathway, phosphoinositide 3 kinase-protein kinase B/Akt-proline rich-Akt substrate 40-mTOR (PI3K-PKB/Akt-PRAS40-mTOR) pathway and phospholipase C-gamma pathways are activated in WHO grade I meningiomas [18-20].