Simple explanation
David Liu's laboratory asked a question that turned out to matter enormously: what if you did not have to cut DNA at all? The answers were base editing, which chemically changes one letter, and prime editing, which writes new sequence directly. Both avoid the double-strand break that makes ordinary CRISPR risky, and both are now in patients.
Go deeper
David R. Liu is the Richard Merkin Professor and director of the Merkin Institute at the Broad Institute, and Professor of Chemistry and Chemical Biology at Harvard. His laboratory developed cytosine base editors (2016), adenine base editors (2017, requiring directed evolution of an enzyme that does not exist in nature for DNA) and prime editing (2019, with Andrew Anzalone). He co-founded Beam Therapeutics, Prime Medicine, Editas Medicine and Pairwise, and was awarded the Breakthrough Prize in Life Sciences in 2025.
Sources
- Nature (Komor et al.) · 2016
Programmable editing of a target base in genomic DNA without double-stranded DNA cleavage ↗ - Nature (Anzalone et al.) · 2019
Search-and-replace genome editing without double-strand breaks or donor DNA ↗