The L1L2_gt0 cassette was inserted at position 29035613 of Chromosome 17 upstream of exon 5 (Build GRCm39). The cassette is composed of an FRT site flanked lacZ reporter/neomycin resistance gene cassette followed by a loxP site. An additional loxP site is inserted downstream of exon 7 at position 29037893. Exons are thus flanked by loxP sites. Exons 5-7 were deleted through subsequent cre-mediated recombination, leaving a reporter-null allele. RT-PCR and immunoblotting experiments indicate that a truncated peptide is produced from this allele. (J:231042)