A lacZ-3pA with a nuclear localization signal and a floxed PGKneo cassette were inserted into exon 1 to create a null allele. Removal of the cre cassette was achieve via a cross to mice carrying the Hprt1tm1(cre)Mnn allele. Absence of transcript was confirmed by RT-PCR on homozygous mice. LacZ expression was confirmed by X-gal staining. (J:125184)