FGFR1 and pilocytic astrocytoma: Duplications of the FGFR1 TKD have also been found in low-grade astrocytomas, including pilocytic astrocytomas and dysembryoplastic neuroepithelial tumors (DNETs), which are typically located outside the cerebellum.144 These mutations are notable features of low-grade neuroepithelial tumors (LGNTs), occurring in 7.4% to 24% of cases, but they are rare in HGGs.