CRISPR/Cas9 technology deleted exon 2. Deletion of exon 2, the first coding exon of the gene, is predicted to result in splicing into exon 3 and the generation of an alternatively spliced isoform that has been seen in human but not in mouse and is predicted to encode a truncated protein. However, transcriptional analysis shows that deletion of exon 2 has a minor effect on transcription and no significant impact on splicing in heterozygotes. RT-qPCR shows a reduction of mRNA levels in E9.5 heterozygous embryos and Western blot analysis shows a 30% reduction in protein levels in E11.5 heterozygous embryos. (J:278323)