This allele from project TCPR0995 was generated at The Centre for Phenogenomics by electroporating Cas9 ribonucleoprotein complexes with single guide RNAs having spacer sequences of CACTTAAGTAAGTACCTGGT and TTAGCTAACATTGTCTGCCC targeting the 5' side and GCCAACTCAAATTTTTACCT and AGCTCTAATAAGAGCCCTTT targeting the 3' side leading to a 385-bp deletion from Chr4:129844869 to 129845253 (GRCm38).