To date, the greatest success in using CAR T cells to target cancer cells has been achieved with targeting CD19+ B-cells in B-cell malignancies such as B-cell non-Hodgkin lymphoma (NHL), Acute Lymphoblastic Leukaemia (ALL) and Chronic Lymphocytic Leukaemia (CLL) [12]. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.