Autologous T cells expressing an anti‐CD19 CAR incorporating the intracellular CD28 costimulatory domain (axicabtagene ciloleucel) have been licensed for the treatment of r/r aggressive B‐NHL, are associated with very high response rates in the treatment of r/r B‐cell acute lymphoblastic leukaemia (B‐ALL) and have led to promising results in the treatment of chronic lymphocytic leukaemia and multiple myeloma.11, 29, 30. The gene discussed is CD28; the disease is precursor B-cell acute lymphoblastic leukemia.