Scientists screened bacterial and archaeal metagenomes to identify, test and begin improving retron‑based self‑priming gene editors compatible with Cas enzymes. The work yielded candidate retrons that function as programmable single‑stranded DNA donors, expanding the toolkit for precision editing and offering alternatives to conventional homology‑directed repair strategies. Authors reported functional testing of multiple retron sequences and suggested retron editors could provide orthogonal editing modalities for microbes and potentially eukaryotic systems after optimization. The study signals growing interest in diversifying editor architectures for difficult‑to‑edit loci and therapeutic applications.