cNK cells, but not ILC22 cells, can be generated with IL-15 and FLT3L. (A) CD34⁺ progenitors were cultured with 4 cytokines (IL-7, IL-15, SCF, and FLT3L) or with only IL-15 and FLT3L. There were no differences in the total numbers of CD56⁺ cells generated under these two conditions (P > .05) (n = 5). (B) Representative FACS plots showing the percentage of CD56⁺ cells and the distribution of cells that show an ILC22 phenotype (IL-1R1⁺ and LFA-1⁻) at day 21 and day 28 in the above culture conditions. (C-D) In cultures lacking IL-7 and SCF, significantly fewer ILC22 cells (CD56⁺LFA-1⁻CD7⁻) were generated at day 21 (P = .029, n = 5) and day 28 (P = .021, n = 5). In contrast, no differences in cNK cells were detected at either day 21 or day 28. D, day; FL, FLT3L; n.s., not significant.