Scientists have engineered new Cas9 proteins that substantially diminish unintended genomic alterations in prime editing, bolstering the precision of this promising genome-editing approach. Prime editing, a CRISPR-derived method, can correct genetic mutations but has faced challenges due to low-frequency off-target errors. The development of these refined Cas9 variants marks a critical step toward safer gene therapies by enhancing editing accuracy and minimizing harmful mutations across multiple target sites.