Cell therapy — most commonly chimeric antigen receptor T-cell (CAR-T) therapy — represents a revolution in cancer treatment: a patient’s own T cells are collected, genetically engineered in a specialized laboratory to recognize specific tumor antigens, expanded to large numbers, and infused back to seek and destroy cancer cells. As a living, one-time treatment, CAR-T can induce deep and durable remissions in patients with relapsed or refractory blood cancers who have exhausted all conventional options. The field is rapidly expanding beyond CD19 and BCMA in hematological malignancies to solid tumor targets, allogeneic ‘off-the-shelf’ products, CAR-NK cells, and in vivo manufacturing approaches.