While we observed a limited but significant decrease in their cytotoxic effect in the initial phases of antigen exposure (e.g., rounds 1 through 6 and round 8), the tumor-killing ability of ITK-KO CD19-CAR-T cells reached levels comparable to those of nt-KO CD19-CAR-T cells at later time points (e.g., rounds 7 and 9) (Figure 4F and Supplemental Figure 4I). The gene discussed is CD19; the disease is neoplasm.