Recent advances in CRISPR-Cas9-based genome insertion technologies.

Programmable genome insertion (or knock-in) is vital for both fundamental and translational research. The continuously expanding number of CRISPR-based genome insertion strategies demonstrates the ongoing development in this field. Common methods for site-specific genome insertion rely on cellular double-strand breaks repair pathways, such as homology-directed repair, non-homologous end-joining, and microhomology-mediated end joining.