PTEN and glioblastoma: Accumulating prospective biomarker alterations for GBM have been confirmed to have major consequences on the management of GBM, such as O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, phosphatase and tension homolog (PTEN) loss, and histone methyltransferase KMT5B alteration (alias SUV420H1) (18–20).