Cre-mediated recombination between loxP sites in intron 4 of Gtf2ird1Gt(XS0608)Wtsi and downstream of exon 34 of Gtf2itm1Lro produced a duplication of the intervening sequence. Western blot analysis confirmed increased expression of Gtf2i but not Gtf2ird1 in the brain. (J:196809, J:222543)