In this transgene insert, a 460 bp Xba-SalI restriction fragment containing a modified Nkx2.2 enhancer Rr209 (where the six core nucleotides within the two putative Tcf4-binding sites were deleted) was placed upstream of a lacZ beta-galactosidase reporter gene cassette (with human beta-globin minimal promoter and poly(A) signal sequence). (J:112802)