IDH1 and neoplasm: Tumours were subtyped using a methylation microarray classifier (Supplementary Fig. 1a and Supplementary Data 6)3; the four subtypes (IDH: 12; MES: 19; RTK I: 12; RTK II: 17) and both major genotypes, IDH wildtype, present in about 90% of primary tumours (MES, RTK I, RTK II; 48), and IDH mutated (IDH; 12) were well represented.