KMT2A and glioblastoma: GBM cells have a characteristic distribution in the tumour microenvironment, with stemlike cells being enriched in the perivascular niche [82], mesenchymal-like cells expressing the transcription factors MLL1 and HIF2a and associated with more hypoxic areas of the tumour microenvironment [17,83,84], and SOX10-positive oligodendrocyte-like cells preferentially existing in the subcortical white matter [85].