ETS1 loss-of-function in CB HPC inhibits NK cell differentiation. (A) Upon transduction with control (ctrl), ETS1 p27, or ETS1 p51 vectors, sorted CB CD34⁺Lin^–eGFP⁺ precursor cells were cultured in NK cell–differentiating conditions. Absolute cell numbers of NK cells were determined at the indicated time points. (B) Absolute cell numbers of differentiation stage 1 to stage 3 were determined at d14. Data are presented as mean ± SEM, and the number of experiments is indicated. Significant difference compared with ctrl, *P < .05 (Student t test).