CD19 and acute lymphoblastic leukemia: They were able to effectively lyse at a effector:target ratio of 5:1 various CD19+ B-cell lines, Daudi (Burkitt’s Lymphoma) co-expressing β2-microglobulin (21) (Daudiβ2m) to reduce lysis by LAC or NK cells (mean ± SD, 44.6% ± 18.2%) and NALM-6 (pre-B ALL; mean ± SD, 38.4% ± 15.1%) in a cytotoxicity assay.