While normal human cells are known to be refractory to transformation in vitro, this study provides a mechanism for the APOBEC3A/B premalignant changes that underpin the creation of many bladder cancer driver genes, such as the most common protein-coding mutation in bladder cancer, which changes Fibroblast Growth Factor Receptor 3 serine 249 into a cysteine “FGFR3S249C” (48–50). This evidence concerns the gene APOBEC3A and urinary bladder carcinoma.