PTEN and glioblastoma: A substantial body of research supports the notion thatneural stem cells (NSCs) within the SVZ may serve as potential cells of origin for GBM.There are many similarities between NSCs and GBM, including low-level mutations intelomerase reverse transcriptase (TERT) and certain oncogenes, such as epidermal growthfactor receptor (EGFR), phosphatase and tensin homolog (PTEN), and tumor protein p53 (TP53)[ 17, 18].