CD19 and neoplasm: When the CD19+ tumor cells (Daudi, Raji, and Raji/eGFP-fLuc) and CD3+ human γ9δ2 T cells were stained with CD19BiTE + a fluorochrome-labeled anti-6 × -histidine mAb, the mean fluorescence intensity detected by the flow cytometry analysis was higher than that in the respective cells stained with a fluorochrome-labeled anti-6 × -histidine mAb alone (Fig. 2c, e, g, l).