Although clinical trials in patients with locally advanced or metastatic FGFR1/3 mRNA-positive urothelial carcinoma have not shown a significant advantage in response, post hoc analysis of patients carrying FGFR3 mutations has shown significantly higher objective response rates than the chemotherapy group, further validating the potential of ctDNA as a biomarker for treatment selection (Sternberg et al., 2023). This evidence concerns the gene FGFR3 and urothelial carcinoma.