CDKN2A and glioblastoma: NF1 alteration (HR: 1.28), PIK3CA/3R1 alteration (HR: 1.25), CDKN2A/B loss (homozygous or heterozygous, HR: 1.21), and increasing age (HR: 1.03) negatively impacted survival for glioblastoma (Figure 4B).