Successful generation of CD38^KO NK cells from ex vivo expanded PB-NK cells using Cas9/RNP. (A) Workflow for generating CD38^KO NK cells from ex vivo expanded PB-NK cells using electroporation of Cas9/RNP. (B) CD38 expression in NK cells before and after Cas9/RNP-mediated CD38 deletion (n = 5; mean ± standard deviation [SD]). (C) Representative fluorescence-activated cell sorter (FACS) analyses of the purified CD38^KO NK cells. Each figure indicates the percentage of CD38-expressing NK cells. Isotype controls are depicted with filled histograms. (D) Expansion of CD38^WT and CD38^KO NK cells.