It is currently only a preprint on bioRxiv, but it has already attracted significant attention from the scientific community and the journal Science. Mammoth Biosciences, a company founded by CRISPR co-inventor Jennifer Doudna, has developed NanoCas, a mini-editor that is just one-third the size of traditional gene-editing scissors (Cas9).

This tool can be easily packaged into an adeno-associated virus and used for in vivo editing of tissues such as muscles and (possibly) the brain, without compromising efficiency. It has been demonstrated to work in mice and monkeys, where it effectively edited a gene linked to Duchenne muscular dystrophy.

Though the system is not yet ready for human trials, it has raised hopes. ‘By expanding the capabilities of genome editing while simplifying delivery, systems like NanoCas represent a crucial step toward realizing this potential for a broader range of genetic diseases,’ write Lucas B. Harrington and colleagues.