CD38^KO/CD38-CAR T cells generated by Cas9/RNP and AAV6 show antitumor activity. (A) CD38 (PE) and CAR (APC) expression levels measured by flow cytometry. (B) Relative percentage of CD38-CAR expression (n = 5; mean ± SD). (C) Ten-day fold expansion of generated CD38-CAR T cells with matched donors (n = 4; mean ± SD). P values were calculated using a 2-way ANOVA; ∗P = .0332; ∗∗P = .0021; ∗∗∗P = .0002; ∗∗∗∗P < .0001. (D) Cytotoxicity of CD38^KO/CD38-CAR T cells toward H929, Raji, and MV4-11 cell lines (n = 4; mean ± SD). P values were calculated using a 2-way ANOVA; ∗P < .05; ∗∗P < .01; ∗∗∗P = .001; ∗∗∗∗P < .0001.