CDKN2A and glioblastoma: In our cohort, 28.8% of EGFR-amplified GBM presented a CT pattern at the EGFR locus (7p11.2) (p < 0.0001), and 19.4% of CDKN2A-deleted GBM harbored a CT pattern at the CDKN2A locus (9p21.3) (p = 0.0003).