© ISTOCK.COM/KMLMTZ66; © ISTOCK.COM/MACROVECTOR
Winston Yan’s graduate school project involved using a variant of the CRISPR-Cas9 genome editing system to knock down a gene that regulates cholesterol in mice. “The real goal was to eventually pave the way for therapeutic uses,” says Yan, who recently completed his graduate work in Feng Zhang’s laboratory at MIT. That’s when he encountered, firsthand, the problem of CRISPR’s off-target effects.
CRISPR allows researchers to quickly and efficiently make targeted cuts to genomes. Its specificity and ease of use gives the gene-editing tool great potential for removing defective genes and treating genetic diseases or cancer, or for editing the genome of crop plants to increase their yield or disease resistance.
To wield this power, however, researchers will first have to overcome one of CRISPR’s ...