In this study, FGFR3 expression was maintained upon UTUC tumor origin, UTUC metachronous IVR, and UTUC metachronous MIBC progression (117/214 (54.7%) UTUC tumor origin, 52/94 (55.3%) IVR, and 9/18 (50.0%) UTUC metachronous MIBC). The gene discussed is FGFR3; the disease is renal pelvis/ureter urothelial carcinoma.