KEGG pathway analysis of the genes containing the 5000 most differentially methylated CpG sites that were hypomethylated in de novo RRD glioblastoma compared to conventional glioblastomas revealed enrichment for specific biologic processes including inositol phosphate metabolism, mRNA surveillance, and neurotrophin signaling pathway (Supplementary Table S6). Here, BDNF is linked to glioblastoma.