Expression of the SV40 early region tumor antigen was driven in mouse prostate epithelium via a rat probasin promoter region fragment (-426/+28 bp). Sequencing identified greater than 20 copies of the Tg(TRAMP)8247Ng transgene (hemizygous) integrated on chromosome 16 (~18,993,000-19,272,880; mouse mm10). The region surrounding the integration site has duplicated. Currently, there are no genes annotated in this region.