Deletion of exons 4-14 of the coding region as follows: A PGK-neomycin cassette flanked by two loxP sites was introduced into intron 3 and a loxP site was introduced into exon 14. Mice positive for the presence of this allele were mated to CMV-Cre transgenic mice to generate mice in which the loxP flanked sequences were deleted. (J:62628)