KIAA1549 and diffuse astrocytoma: Single driver genetic alterations have been consistently identified within specific histologic subtypes of pediatric LGGs, including BRAF-KIAA1549 fusions in pilocytic astrocytomas [29, 54], BRAFV600E point mutations in pleomorphic xanthoastrocytomas and gangliogliomas [17, 68], FGFR1 duplications in diffuse astrocytomas [68], and MYB or MYBL1 rearrangements in diffuse astrocytomas and angiocentric gliomas [4, 49, 58].