highly significantp < 0.0001
39 Billerey and colleagues detected FGFR3 alterations in 27 (84%) out of 32 grade (G)1 NMIBCs, 16 (55%) out of 29 G2 tumors, and 5 (7%) of 71 G3 tumors, with a highly significant association ( p < 0.0001) between FGFR3 mutations and low-grade disease. 40 FGFR3 mutations have also been detected in around 10% of MIBCs. 41 , 42 The most frequent types of FGFR3 aberrations in UCs are activating mutations. 21 , 34 FGFR3S249C, the most common aberration (21%), induces ligand-inde