The insertion of the L1L2_Bact_P cassette created a deletion of size 6642 starting at position 72673453 and ending at position 72680095 of Chromosome 11 (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 neomycin resistance gene under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site, and subsequent Cre-mediated excision deleted the neomycin selection cassette.