The L1L2_Pgk_P cassette was inserted at position 71388346 of Chromosome 9 upstream of the exon 2 (Build GRCm39). The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site is followed by a neomycin resistance gene under the control of the PGK promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site is inserted downstream of exon 3 at position 71391587. The critical exons, 2 and 3, are thus flanked by loxP sites. A "conditional ready" (floxed) allele was created by flp recombinase expression. Subsequent cre expression results in a knockout mouse. Further information on targeting strategies used for this and other IKMC alleles can be found at http://www.informatics.jax.org/mgihome/nomen/IKMC_schematics.shtml