Life-long prophylaxis or treatment through a single administration of a gene therapy vector would be transformative for many diseases, including HIV, but irreversible intervention is not without risk. In case of adverse events, it would be important to have the option of inactivating the therapeutic gene or vector. Dr. Guocai Zhong’s research focuses on developing switches for controlling therapeutic genes delivered by gene therapy vectors. In addition to turning off a therapeutic gene in case of adverse events, switching technology enables dosing. The ability to inactivate or reduce the dose of a therapeutic gene is an important safety feature.