Anti-CCR9 CAR-T cells demonstrate potent cytotoxicity against primary T-ALL blasts in vitro. (A,C,D) NT, CAR19, or CARCCR9 cells from healthy donor T cells were incubated for 72 hours, at a 1:1 ratio with T-ALL blasts obtained from 3 separate patients. Flow cytometry of sample CCR9 density (left), quantification of remaining blasts (middle), and interferon-γ (IFN-γ) secretion (right) in patients 1 to 3, respectively. (B) Example flow cytometry gating from patient 1 at end of coculture. **P < .01, ***P < .001, ****P < .0001. CTV, CellTrace Violet; ns, not significant.