The insertion of the L1L2_Bact_P cassette created a deletion of size 1935 starting at position 164612282 and ending at position 164614217 of Chromosome 2 (Genome Build GRCm39). This deletion results in the removal of functionally critical exon(s). The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site was followed by a neomycin selection cassette under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site. Expression of cre recombinase excised the neomycin selection cassette. (J:148605, J:173534, J:188991)