A new Nature study describes “prime assembly,” a genome engineering method designed to integrate long DNA fragments into precise, programmable genomic target sites. The approach extends prime editing by using CRISPR-targeted dual flap synthesis, allowing site-specific placement of larger insertions and programmable rearrangements in living cells. The researchers demonstrated prime assembly for exon recoding, transgene integration, and megabase-scale rearrangements in primary human cells, including therapeutically relevant loci. The authors and independent experts framed prime assembly as potentially less likely to introduce off-target effects because it avoids reliance on double-strand breaks typical of other strategies. Taken together with another contemporaneous write-up emphasizing multi-mutation correction potential, the work strengthens the case that prime assembly could support more universal gene therapy designs rather than one-off, patient-specific edits.