m909-28Z CAR T cells prevent THP1 AML tumor growth in vivo. THP1-fLuc cells (5 × 10⁶) were injected into (NOD/SCID)/γ-chain^−/− mice subcutaneously on day (d)0. CAR⁺ T cells (5 × 10⁶) were given intraperitoneally on days 8 and 10. Tumor growth was monitored by luminescence (A-B) and by caliper measurement (C). Graphs represent mean ± SEM of n = 5 mice per experiment. P values were calculated compared to CD19-28Z–treated control mice. Differences between GFP and CD19-28Z groups did not reach statistical significance at any time point. (D) Preferential expansion and survival of peripheral human T cells in m909-28Z–treated mice compared to control T cells. Peripheral blood was collected on day 38 (4 weeks post–T-cell injection), and absolute numbers of human CD3⁺ (left), CD8⁺ (middle), and CD4⁺ (right) T cells were quantified by flow cytometry and are reported in total cells per microliter of blood. *P < .05; **P < .01. ns, P > .05.