Three nucleotides (AAG) were deleted from exon 8, effectively deleting glutamic acid codon 385 (p.E385delE, GRCm39:chr1:g.58883848_58883850delAAG), using an sgRNA and an ssODN template with CRISPR/Cas9 technology. The deletion is in the auto-cleavage site of the encoded peptide and affects its enzymatic activity by blocking auto-cleavage. (J:342732)