Paucity of NK-cell progenitors in blood from patients with GATA2 mutation. NK-cell or CD3⁻CD20⁻CD14⁻CD16⁻CD56⁻ (Lin⁻) cell populations were cultured with irradiated B-LCL feeder cells and IL-2. (A) Charts depict expansion kinetics of total NK cells and Lin⁻ cells up to 14 day of ex vivo expansion. (B) Representative flow plots of control, GATA2 exonic/splicing mutation, and GATA2 intron 5 mutation. CD16 and CD56 expression on gated mononuclear CD3⁻CD20⁻CD14⁻ cells is shown. Total NK cells and Lin⁻ cells were sorted and cultured separately for 14 days. Lin⁻ cells were sorted and stimulated again from day 14 Lin⁻ cell culture for another 14 days (shown as day 28). (C-E) NK-cell subpopulations frequencies of (C) pre-expansion, day 14 total NK cells, (D) day 14 Lin⁻ cells, and (E) day 28 Lin⁻ cells are shown in comparison. (F) Relative GATA2 expression levels in sorted control Lin⁻ cells compared with control CD16⁻CD56⁺ cells at day 1 (n = 4) and day 14 (n = 2) ex vivo culture. Bars indicate mean ± SD. *P < .05, **P < .01, and ***P < .01.