Researchers unveiled small-molecule-controlled CRISPR systems designed to switch genome editing on only when dosing triggers are present. In a Science Translational Medicine paper, a team led by Dr. Wang Yu at the Shenzhen Institutes of Advanced Technology of the Chinese Academy of Sciences reported PRINCE and Little Prince—dual systems intended to keep CRISPR largely silent without the drug inducer. The approach aims to improve therapeutic controllability by limiting editing activity to defined time windows, addressing a common translational challenge for gene-editing platforms. “On-demand” control here refers to chemically induced activation of the editing machinery in living tissues. If the systems hold up in further preclinical and clinical testing, they could support safer dosing strategies for in vivo editing where off-target or prolonged activity is a concern.