CDKN2A and glioblastoma: Accordingly, patients with IDH‐wildtype GBM could be classified into three groups with different prognoses—good prognosis: patients with methylated MGMT status, intermediate prognosis: patients with unmethylated MGMT status and without CDKN2A homozygous deletion, and poor prognosis: patients with unmethylated MGMT status and CDKN2A homozygous deletion (Figure 1C).