MTOR and glioblastoma: Since aberrant activity of the PI3K/AKT/mTOR pathway is commonly observed in cancer, mTOR inhibitors (e.g., Everolimus, Deferolimus, and Temsirolimus) have emerged as promising therapeutic agents for the treatment of a variety types of cancer, including renal-cell carcinoma, breast carcinoma, non-small-cell lung carcinoma, endometrial carcinoma, glioblastoma, and mantle cell lymphoma (Chapman and Perry, 2004; Rowinsky, 2004; Vignot et al., 2005; Hartford and Ratain, 2007).