These FGFR family alterations included gain-of-function sequence variants (n = 19), amplifications (n = 10), oncogenic fusions [FGFR3:TACC3 (n = 3), FGFR1:TACC1 (n = 1), FGFR1:EBF2 (n = 1), FGFR1:CLIP2 (n = 1), and FGFR2:CTNNA3 (n = 1)], pathogenic-leaning variants of uncertain significance (n = 4), and amplification in combination with a pathogenic-leaning variant of uncertain significance (n = 1), identifying a population of children with cancer who may be good candidates for FGFR inhibitor treatment. Here, FGFR3 is linked to cancer.