Consistent with these recent findings, none of our sporadic UTUC has a mutator phenotype, and the majority of cases have luminal papillary-enriched transcriptome signatures, although caution might be considered in interpreting the results, as almost half of the cases assessed had FGFR3 mutations and were NMI tumors. Here, FGFR3 is linked to renal pelvis/ureter urothelial carcinoma.