An 898 bp fragment surrounding the first coding exon was replaced with a floxed neo cassette. Cre mediated recombination was then used to remove the floxed neo cassette. No phenotypic difference was reported between the neo in and neo out versions of this allele. Northern blot analysis detected the expression of an abnormal 2.0 kb RNA. RT-PCR and 5' RACE analysis indicate that this RNA includes exons 2-8 of the endogenous gene and a region from the first intron. Cell expression analysis indicates that the abnormal RNA would not produce a stable protein.