PTEN and glioblastoma: GBM cases showed chromosomal gains in chromosome 7 (36.0%); losses in chromosomes 10 (26.0%) and 9 (26%); and focal alterations, including EGFR (7p11.2) amplification (27.2%), PTEN (10q23) alterations (13.6%), and CDKN2A/B (9p21.3) deletions (22.2%).