FGFR1 and glioma: In combined pediatric brain tumor databases, the rates of alterations of the FGFR1, FGFR2, FGFR3, and FGFR4 genes were 1.4%, 0.3%, 0.1%, and 0.2%, respectively, with FGFR1 and FGFR4 gene alterations found in up to 5% of pediatric gliomas while FGFR2 and FGFR3 alterations were less common but found most frequently in medulloblastoma [Figure 3].