Researchers led by Wang Yu at the Shenzhen Institutes of Advanced Technology of the Chinese Academy of Sciences reported dual small-molecule-controlled CRISPR editing systems, PRINCE and Little Prince, published in Science Translational Medicine. The approach is designed to switch genome editing on with drug inducers and keep it largely silent in their absence. The work adds to the push for controllable therapeutic genome editing by addressing a key safety and precision challenge—minimizing unintended activity between dosing windows.