In a study conducted at the Memorial Sloan-Kettering Cancer Center 10 patients with chemotherapy-refractory chronic lymphocytic leukaemia (CLL) or relapsed B cell acute lymphoblastic leukaemia (ALL) were treated with CD19 CAR T cells containing both the CD28 and CD3 zeta signalling domains 70. Here, CD28 is linked to B-cell chronic lymphocytic leukemia.