Arginine codon 90 (CGC) in exon 4 was changed to histidine (CAC) (p.R90H) using an sgRNA (targeting ACGAGCCGCTGAGAGTCGCC) and an ssODN template (CATGGGTCTCTGGCTCCCCCACCCAGCACCCAGGTGGTTTGATGGGCAACGAGCAGCTGAGTCCCACCAGGGCACTCTCACTGAATACTTCAACGGCCTCATGGGACTGCCCGTGAAGAT) with CRISPR/Cas9 technology. The mutation (SNP rs201802880) is found in some systemic lupus erythematosus (SLE) patients.