Gene therapy has been heralded as the new frontier of medicine, but there are still many limitations to current technologies; among them, how to deliver therapeutic genes to specific cells, and only activate them in the right context. A team has created a new RNA-based tool called DART VADAR to bring gene editing out of the ‘dark side’ of those problems and into the light. Using an engineered form of a naturally occurring enzyme, their sensors can automatically sense the presence of a trigger molecule and initiate the translation of payload genes within cells. The advance broadens the scope of conditions that can be treated with RNA-based therapeutics and enables the development of highly specific treatments for a variety of diseases.