10 adult patients with chemotherapy-refractory chronic lymphocytic leukemia (CLL) or relapsed B-cell acute lymphoblastic leukemia (ALL) have been enrolled for treatment with autologous T cells modified to express 19–28z, a second-generation chimeric antigen (Ag) receptor specific to the B-cell lineage Ag CD19. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.