This allele was generated, along with Hnf4tm1.1Gonz, by breeding mice carrying Hnf4tm1Gonz with transgenic mice expressing cre recombinase via the EIIa promoter. Expression of cre resulted in the excision of exons 4 and 5 as well as the floxed neomycin cassette. Northern blot and RT-PCR analyses identified a truncated transcript. Sequence analysis showed that the deletion intoduced a frameshift mutation via the splicing of exons 3 and 6. Western blot analysis confirmed the presence of a shortened peptide, putatively lacking several functional domains, including the A and T boxes, the ligand-binding domain, and the activation function 2 domain.