The transgene contains a 2.34 kb mouse albumin enhancer/promoter (M. Magnuson verified mouse promoter, personal communication), a nuclear localization sequence-modified Cre recombinase gene and a 2.1 kb fragment from the human growth hormone gene. The promoter is active in hepatocyte cells of the liver. 7 copies of the transgene are estimated to be present. Line 21 inserted into the gene at 3172116-3172120 (Build GRCm38/mm10) resulting in a 4 bp deletion. Founder line x has a copy number of approximately 10.