CD7ΔCD7-CAR-T cells exert specific cytotoxicity to CD7+ cells in an antigen-density-dependent manner in vitro. A. Flow cytometry diagram showing the overexpression of CD7 in HEK-293T cells. GFP was used as the detection marker following its co-expression with the CD7 antigen. B. Normalized cell index of 293T-CD7 cells incubated with or without CD7ΔCD7-CAR-T cells. Data were acquired by RTCA. C. The cytolysis activity of CD7ΔCD7-CAR-T cells was evaluated with primary leukemia cells from patients with T-ALL, non-transduced T (NT), and CD7ΔT cells (each with a different CD7 MFI) at a 1:2, 1:1, 2:1, and 4:1 E:T ratios for a 24 h incubation assay. The mean (±SD) of triplicate experiments are shown. The graph shows statistical analysis of CD7 MFI in primary T-ALL and NT cells. D. Bars represent the mean (±SD) of cytokine secretion which was assessed with a CBA kit by flow cytometry.