GAS1 and glioblastoma: GBM cases belonging to the classical subtype are also characterized by the high expression of genes belonging to the notch homolog 1, translocation-associated (NOTCH) pathway such as neurogenic locus notch homolog-3 (NOTCH3), jagged-1 (JAG1) and lunatic fringe (LFNG), sonic hedgehog pathway such as smoothened (SMO), growth arrest-specific protein 1 (GAS1) and zinc finger protein GLI1 (GLI1) and the neural precursor and stem cell marker nestin (NES) pathway (Tcga, 2008; Verhaak et al., 2010; Brennan et al., 2013; Wang et al., 2016).