IDH2 and astrocytoma (excluding glioblastoma): Among 23 CNS WHO grade 4 tumors with available 450 k DNA methylome data, a similar trend of lower LINE-1 methylation levels in “astrocytoma, IDH-mutant, high-grade” tumors was observed, albeit the p value remained insignificant likely due to the low number of tumors assigned to the methylation class “astrocytoma, IDH-mutant, lower grade” among the CNS WHO grade 4 tumors (Fig. S5b).