On the other hand, most of the hemizygous Tp53 mice developed tumors, but there were no significant differences in OS, EFS, or cumulative incidence of tumor development between A3B+ p53+/− and A3B− p53+/− mice (Figure 3A–C), indicating that A3B overexpression did not affect the onset of tumors and did not cause tumor promotion under a hemizygous Tp53 background. This evidence concerns the gene APOBEC3B and neoplasm.