The L1L2_Pgk_P cassette was inserted at position 113051633 of Chromosome 12 upstream of the critical exon(s) (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 the targeted exon(s) at position 113052817. The critical exon(s) is/are thus flanked by loxP sites. Cre mediated recombination without flp expression produced a reporter 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