Genetic alterations in the PI3K–AKT signaling pathway were observed in about 35–67% of FGFR3-TACC3 fusion-positive clinical samples (Supplementary Table S5).25 Therefore, we would need to examine PI3K/AKT status when we treat FGFR3-TACC3 fusion-positive cancer with the FGFR inhibitor. Here, TACC3 is linked to cancer.