Exon 4, which contains the sequence coding for zinc finger 5, and parts of intron 3 and 4 were replaced with a neo cassette. Deletion of zinc finger 5 (ZF5) is predicted to disrupt DNA binding ablity and transcriptional activity of the gene. The inability of the protein produced from this allele to activate transcription of a luciferase reporter with a Glis-binding site was confirmed by cellular assay.