These findings have prompted the FDA to approve anti-CD19 CAR T cells as the first T cell therapy even for refractory ALL and diffuse large B-cell lymphoma.11,12 More CARs are currently undergoing clinical development for the treatment of other haematological entities, such as chronic lymphocytic leukaemia, or low grade lymphomas and myeloma.13,14 It is consequently likely that there will be an increase in approvals for the use of CAR T cells across a wider array of malignancies. Here, CD19 is linked to acute lymphoblastic leukemia.