PTEN and glioblastoma: Several genes associated with GBM development have been identified as representative molecular biomarkers, such as isocitrate dehydrogenase 1 (IDH1) mutations, chromosome 1p19q co‐deletion, O6‐methylguanine‐DNA‐methyltransferase promoter methylation, phosphatase and tensin homolog (PTEN) mutations, and EGFR variant III (EGFRvIII) amplification (Hill et al., 2003; Rich et al., 2005; Wang et al., 2015).