The APOBEC3A and APOBEC3B cytosine deaminases are the main mutators of bladder cancer genomes (evidenced as COSMIC SBS2 and SBS13 mutational signatures in 93% of bladder tumours [13]) and therefore account for most of the neoantigen load in bladder tumours. This evidence concerns the gene APOBEC3B and urinary bladder neoplasm.