One study looking at mutations in UTUC identified TP53, PIK3CA, and FGFR3 mutations as possible driver mutations, differing from urothelial carcinoma of the bladder; as well, patients with UTUC had lower PD-L1 expression than those with bladder cancer [19]. Here, FGFR3 is linked to renal pelvis/ureter urothelial carcinoma.