IDH1 and glioma: The proneural subtype is found to be closely linked to amplifications in platelet-derived growth factor receptor A (PDGFRA) and mutations in isocitrate dehydrogenase 1 (IDH1), which causes global hypermethylation and a phenotype called glioma-CpG island methylator phenotype (G-CIMP) [7,8,9].