For example, in a cohort of patients aged ≥80 years with IDH-wildtype glioblastoma, tumor-specific therapy conferred a median OS benefit of 2.1 months versus best supportive care (BSC), but only in patients with MGMT promoter methylation (median benefit of 3.6 months) while no benefit was observed in patients without MGMT promoter methylation (113). Here, IDH1 is linked to glioblastoma.