However, many results from experiments utilizing the 5210-87-13 mAb are still interpretable and, in many instances, definitive, as: (1) A3B was the only one of these enzymes expressed in the system (e.g., transient transfections and many different cancer cell lines and tumor tissues); (2) the three enzymes can be distinguished by kilodalton size and mobility (immunoblots); and (3) the enzymes localize to different subcellular compartments (A3B shows nuclear localization, whereas A3A and A3G are cytoplasmic). This evidence concerns the gene APOBEC3B and cancer.