PTEN and brain cancer: Numerous genetic mutations identified in brain cancers include the tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), neurofibromatosis type 1 (NF1), epidermal growth factor receptor (EGFR), retinoblastoma (RB), and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) [5].