CRISPR, or clustered regularly interspaced palindromic repeats, is transforming biomedical research, and making rapid inroads into the clinic, with its ability to easily target specific DNA and RNA sequences. CRISPR itself is made of RNA. It recognizes target sequences and delivers CRISPR-associated (Cas) proteins, nucleases that cut the target sequence. In two papers published online in Nature on Jan. 4, 2023, researchers have demonstrated that a recently discovered type of Cas protein, Cas12a2, can degrade double-stranded DNA when its associated CRISPR guide RNA recognizes its target sequence.