In fact, the most frequent copy number alterations were 7p11.2 amplifications (EGFR locus), 9p21.3 deletions (CDKN2A locus) and 10q23.31 deletions (PTEN locus), that are typical features of primary GBM, essential for gliomagenesis [44]. This evidence concerns the gene PTEN and glioblastoma.