CD4 and acute lymphoblastic leukemia: We compared specific cytotoxicity of both CD4 and CD8 TN-enriched CAR T cells produced using clinical vector BAFF-R:4-1BB:ζ/EGFRt and prototype vector BAFF-R:4-1BB:ζ/GFP using an vitro cytotoxic T lymphocyte (CTL) assay [15] in a panel of chromium-51 labeled target malignant B-cell lines including Nalm-6 B-ALL (Fig. 1c).