EPFL researchers reported DROP‑CAR, a CAR‑T cell design that can be rapidly and reversibly switched off using the approved cancer drug venetoclax. In preclinical mouse models the system enabled clinicians to disengage CAR‑mediated cell–cell interactions without killing the engineered T cells, offering a potential safety control for on‑target, off‑tumor toxicity and chronic antigen exposure. The team published their findings in Nature Chemical Biology and highlighted the clinical realism of using an existing small molecule as a remote control for CAR activity. The approach could expand CAR‑T applicability to solid tumors by giving physicians a tunable safety knob during treatment.