The CRISPR/Cas9 system is a very versatile tool for a wide variety of genetic changes, including deletions, point mutations, and insertions. The Cas9 nuclease contains two active sites. When both sites are active, Cas9 binds to a guide RNA molecule and causes targeted double-strand breaks (DSBs) in genomic DNA. The CRISPR system can also be used due to the presence of donor DNA molecules homologous to the target region. Specific nucleotide modifications are introduced into the sequence of interest during homologous recombination. Compared to traditional methods, the CRISPR-Cas9 system has significant advantages, including lower cost, shorter timeline and the ability to simultaneously change multiple genes.