FGFR1 and astrocytoma (excluding glioblastoma): Other molecular differences between paediatric and adult astrocytomas include the increased frequency of ACVR1, ATRX, H3F3A, KIAA1549‐BRAF, fibroblast growth factor receptor 1 (FGFR1) mutation and fusions, SET domain‐containing 2 (SETD2),83PDGFR‐α and P53 mutations in paediatric tumours compared to relatively low to no mutations in adults.75, 76