This allele was generated at The Jackson Laboratory by electroporating Cas9 protein and 2 guide sequences GCAGGCACTAGATTATTCAG and AGCAGACTCCCACTCACAAG, which resulted in a 2400 bp deletion beginning at Chromosome 2 position 131,211,143 bp and ending after 131,213,542 bp (GRCm38/mm10). This mutation deletes ENSMUSE00000558540, ENSMUSE00001373302, ENSMUSE00000558538 (exons 2, 3, and 4) and 1210 bp of flanking intronic sequence including the start site, splice acceptor and donor and is predicted to result in a null allele.