RB1 and glioblastoma: In glioblastoma, molecular and clinical features remained largely stable, including PIK3CA/3R1 alteration (HR: 1.31, P < .01), CKDN2A/B loss (HR: 1.22, P = .01), increasing age (HR: 1.03, P < .001), RB1 alteration (HR: 0.79, P < .05), 19q gain (HR: 0.70, P < .001), 21q loss (HR: 0.55, P < .002), methylated MGMT (HR: 0.46, P < .001), and receipt of chemotherapy (HR: 0.37, P < .001).