FGFR3 and cancer: Given the mutual exclusion of FGFR3 and TP53 gene mutations in UC, the decreased frequency of FGFR3 mutations alongside the advancement of tumor stage and grade of dysplasia may be due to the fact that FGFR3-mutated tumors rarely progress, and most advanced cancers would derive from precursors with mutations in a different pathway for tumor development [26].