The entire human AGT genomic sequence containing an A to G nucleotide substitution at position -6 of the promoter was inserted into the Hprt locus via homologous recombination. (This polymorphism has been reported in association with hypertension in humans.) RNase protection assay showed transgene expression in liver, kidneys, brain, and aorta. In addition, immunohistochemical analysis and Western blot detected transgene expression in the kidneys and plasma, respectively.