As we found A3B1 the primary mutagenic APOBEC enzyme in bladder tumors, enhancing A3B exon 5 skipping might help to restrict APOBEC-mediated mutagenesis, including FGFR3-S249C mutation in bladder cancer, as well as prevent tumor progression and recurrence, clonal evolution, and resistance to chemotherapy (Fig. 8). This evidence concerns the gene APOBEC3B and urinary bladder carcinoma.