Methylation of the AKT1, GSK3β, EGFR, PTEN (p < 0.001), and AKT2 (p = 0.018) genes was significantly lower in GBM, while the AKT3 and CHUK (p < 0.001) genes were significantly more methylated in GBM versus DA. Here, PTEN is linked to glioblastoma.