In humans, ATRX loss is frequently involved in formation of gliomas, in particular in combination with mutations in IDH (low and high‐grade astrocytoma, [183]), histone H3 G34 (hemispheric high‐grade glioma) [184], H3 K27M (midline glioma) [184], or MAP kinase pathway activation (posterior fossa high‐grade astrocytoma with piloid features) [185]. Here, IDH1 is linked to astrocytoma (excluding glioblastoma).