IDH1 and glioma: 53,869 differentially methylated positions (DMPs) with Benjamini–Hochberg adjusted p value < 0.05 and a methylation difference > 20% were identified between PM gliomas and normal brain tissues; 96% of these sites were hypermethylated in the PM gliomas, confirming the hypermethylator phenotype of IDH-mutant gliomas.