This allele is derived from Hinttm1Tpm by crossing mutant animals to cre deleter strain Tg(Pgk1-cre)1Lni. Exons 2 and 3 were deleted by homologous recombination between flanking loxP sites. A single loxP site and a PGK-neo cassette remains in the place of exon 2 and exon 3. (J:83562)