FOXO1 and CAR T (IMAGE) Children's Hospital of Philadelphia Caption Like a lightbulb, CAR T cells designed to kill cancer often burn out due to exhaustion and poor persistence. Doan et al. discovered that a transcription factor called FOXO1 is responsible for keeping the CAR T lightbulb energized by activating genes which counteract exhaustion, promote persistence, and enhance CAR T cell antitumor activity. (Artwork by Gerardo Sotillo) Credit Gerardo Sotillo, Stanford Medicine Usage Restrictions Only use as accompaniment to this story. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.