FGFR3 and bladder transitional cell carcinoma: In a study with cell lines derived from urothelial bladder cancer (MGH-U3 (Y375C FGFR3 mutation) and RT112 (FGFR3-TACC3 fusion)), upregulated MYC expression due to constitutively activated FGFR3 has been described and, in addition, MYC has also been shown to be a direct positive regulator of FGFR3 expression at the transcriptional level forming an FGFR3/MYC positive feedback loop [91].