Receiver operating characteristic (ROC) analysis showed that the areas under the receiver operating characteristic curve (AUCs) for the tumour grade (GBM vs lower grade astrocytoma), MGMT promoter methylation status, IDH mutation status, AP score and combined factor of the IDH status and AP score were 0.7543, 0.6509, 0.8220, 0.8367 and 0.8513, respectively, in the training cohort (Supplemental Fig. S1). Here, IDH1 is linked to astrocytoma (excluding glioblastoma).