The insertion of the L1L2_Bact_P cassette created a deletion of size 1256 starting at position 107958320 and ending at position 107959576 of Chromosome 9 (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 is followed by a neomycin resistance gene under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site.