IDH1 and astrocytoma (excluding glioblastoma): To investigate biological associations underlying malignancy of IDH-mutant astrocytomas, four large multi-domain and multi-centre omics datasets were leveraged: CATNON, TCGA, GLASS-NL primary (GLASS-NL-P) and GLASS-NL recurrent (GLASS-NL-R) [1, 7, 41].