Cytotoxicity at NALM6 leukemia lymphocyte cells mediated by primary T-cells, modified by CD19-CD22 dual CAR integration under each enGager transfection condition, were determined at Effector (T cell): Target (NALM6 cells) ratios of 2.25:1, 4.5:1 and 9:1. This evidence concerns the gene CD19 and leukemia.