CDKN2A and glioblastoma: Of all 26 MGMT methylated glioblastomas, twelve showed CDKN2A/B loss while 14 showed retained CDKN2A/B (Figure 3E), and of all 19 MGMT unmethylated glioblastomas eight showed CDKN2A/B loss while 11 showed retained CDKN2A/B (Figure 3F).