PIK3CA and glioblastoma: The fact that the activation of mTORC1 by the PI3K/PTEN/Akt pathway alone does not correlate with epithelioid morphology is supported by the astrocytic/fibrillary appearance of the overwhelming majority of glioblastoma cases, which belong to the so-called “classic” variant and exhibit PI3K/PTEN/Akt pathway activation, mainly via inactivation of PTEN tumor suppressor [26–30].