Use exclusive Red Cotton system to design a sgRNA fragment knockout strategy for the BICD2 gene, clone the two sgRNAs into CRISPR-U™ vector, transfect the vector into the 293T cell line by electroporation/lentivirus method, use the limited dilution method for single-cell cloning and use the EZ-editor™ Monoclone Genotype Validation Kit (Cat# YK-MV-1000) for nucleic acid lysis and PCR amplification on the single-cell clones, followed by Sanger sequencing to verify the genotype. Upon passing the verification, BICD2 gene knockout BICD2 Knockout cell line (293T) will be expanded and cryopreserved.