Notably, FGFR1-TKDD has not been identified in adult-type oligodendrogliomas with IDH mutations and 1p/19q codeletion.145,146 Additionally, there was a case report of a glioneuronal tumor with features of both pilocytic astrocytoma and pleomorphic xanthoastrocytoma, which also carried FGFR1-TKDD and showed focal increases in mitotic activity.147 These findings highlight the range of gliomas associated with FGFR1-TKDD mutations and the need for further study to understand their clinical significance and potential treatment approaches. The gene discussed is IDH2; the disease is oligodendroglioma.