Given the involvement of FGFR3-driven and/or RAS/MAPK signaling activation in tumorigenesis, including UTUC development [19,23], we next observed the molecular alterations in the UTUC cells receiving FGFR3 siRNA or scramble non-target control transfection. Here, FGFR3 is linked to renal pelvis/ureter urothelial carcinoma.