Twin prime editor: seamless repair without damage

CRISPR-Cas9 creates remarkable possibilities to modify targeted regions in genomic DNA. However, CRISPR-Cas-mediated DNA double-stranded breaks (DSBs), that tend to generate random insertions or deletions, limit this technology. Recently, Anzalone et al. developed a 'twin prime editing' tool to replace, integrate, or delete large genomic DNA sequences without generating DNA DSBs.