Researchers screened metagenomic datasets and identified retron reverse transcriptases that generate intracellular single‑stranded DNA, then validated and engineered those elements as programmable retron editors for precise genome modification. The work, highlighted in a Nature Biotechnology report and linked lab studies, positions retrons as complementary editors to Cas enzymes, particularly for edits requiring donor DNA templates inside cells. Teams reported initial in‑cell activity and outlined early optimization paths to improve efficiency and target scope.