The targeting construct consisting of an F3 site, a neomycin resistance cassette, CAG promoter, loxP-flanked transcriptional termination cassette, FLAG-HA tagged human GFAT1 open reading frame, human growth hormone polyadenylation signal and additional polyadenylation signal and FRT site were inserted into the locus. Upon cre-mediated recombination, the STOP cassette can be removed to get expression of the human GFAT1 under the control of the CAG promoter. (J:340718)