CD19 and acute lymphoblastic leukemia: Furthermore, autologous CD19RCD28+ and CD19RCD137+ T cells displayed minimal lysis of EL4 and EL4-ROR1 but lysed both Kasumi-2 and NALM-6 (both CD19+) suggesting that the ROR1RCD28+ and ROR1RCD137+ T cells were more discriminant in their targeting of these B-ALL cell lines (Fig 5a bottom).