Chimeric antigen receptor (CAR) T cells are genetically engineered immune cells that can seek out and destroy cancer cells. The results from their use in cancer immunotherapy have been very promising, but treatment is often associated with frequent, serious short-term toxicities. 'Fast Facts: CAR-T Therapy' explains what CAR T cells are and how they were developed, discusses the results of clinical trials and the management of toxicities, and outlines future improvements and applications. It is ideal reading for any healthcare professional wanting to know more about this exciting therapeutic field.