Two FRT sites have been inserted into the endogenous Hnf4 locus. The first is in a 5' intron and the second is downstream of the 3' end of the gene. A Disc\RFPDsRed.3xP3.cUa reporter has also been inserted, downstream of the stop codon but upstream of the second FRT site. This results in a conditional allele; FLP recombinase can be used to excise the artificial FRT cassette, excising most of the Hnf4 gene, disrupting its function. Excision of the FRT cassette also removes the Disc\RFPDsRed.3xP3.cUa reporter.