II. To perform archival tumor analysis for markers of dysregulated cell signaling that may predict response to mechanistic target of rapamycin (mTOR) inhibitor therapy such as epidermal growth factor receptor (EGFR) (expression by immunohistochemistry [IHC] and amplification by fluorescent in situ hybridization [FISH]), phosphatase and tensin homolog (PTEN) (expression by IHC and deletion by FISH), phosphorylated (p)-protein kinase B (AKT), p-ribosomal protein S6 kinase (S6K), p-eukaryotic translation initiation factor 4E binding protein 1 (4EBP), p-mTOR and p-mitogen-activated protein kinase 1 (Erk) in patients with recurrent GBM.