Expanded CD7^KOCD7 CAR T cells eradicate T-ALL and T lymphoma cell lines. (A) Surface expression of CD7 (solid histograms) in T-ALL and T-lymphoma cell lines measured by flow cytometry in comparison with isotype control (open histograms). (B) Tumor cell lines were labeled with eFluor670 and cocultured with CD7^KO CD7 CAR T cells at the effector-to-target ratio 1:4 for 3 days. Dot plots show frequency of gated live tumor cells (CCRF) at the end of coculture. (C) Absolute counts of live tumor cells were measured by flow cytometry using counting beads at the end of coculture with CD7^KO CD7 CAR T cells. CD7⁻ cell line NALM6 was used as a negative control. Dashed lines represent the initial number of tumor cells on plating. (D) Representative dot plots showing intracellular cytokine staining for TNFα and IFNγ in CD7^KO CD7 CAR T cells upon coculture with CCRF cells or media alone. (G) Mean frequencies of cytokine-positive CD4⁺ (top) and CD8⁺ (bottom) CD7^KO CD7 CAR T cells on coculture with indicated CD7⁺ cell lines or media alone. Data represent 2 independent experiments with n = 3 donors in each. **P < .01; ***P < .001; ****P < .0001.