By fusing MCM5, a subunit of the eukaryotic MCM2–7 helicase complex, to the N terminus of spCas9 (MCCas), the MCCas fusion protein enhances large-size fragment knockin via homologous recombination, reduces insertions and deletions (indels), and enables efficient large-size fragment insertions in human cells and rabbit embryos.

Nature, Published online: 15 April 2026; doi:10.1038/s41586-026-10416-8A genome-to-genome association study identifies host and viral risk factors that interact to drive nasopharyngeal carcinoma endemicity in southern China.