The L1L2_st0 cassette was inserted at position 83216646 of Chromosome 4 upstream of the critical exon(s) (Build GRCm39). The cassette is composed of an FRT flanked lacZ/neomycin sequence followed by a loxP site. Insertion of this cassette creates a reporter knockout mouse. Cre expression will remove the neomycin selection cassette. 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