Thymic NK cells can be generated from early thymic progenitors as well as Lin⁻CD122⁺NK1.1⁻DX5⁻ NK-/T-cell progenitors in the BM. (A) Ten DN1 cells (Lin⁻CD25⁻Kit^high) sorted from the thymus of 6- to 9-week-old mice and (B) 5 Lin⁻CD122⁺NK1.1⁻DX5⁻ NKPs sorted from BM of 9- to 12-week-old mice were cultured on OP9DL1 stroma for 21 days in the presence of KL, FL, and IL-15. Generated clones were evaluated by FACS for the presence of BM-dependent NK (TCR-β⁻NK1.1⁺CD122⁺IL-7Rα⁻), thymic NK (tNK; TCR-β⁻CD25⁻Ly49D⁻ NK1.1⁺CD122⁺IL-7Rα⁺), T (TCR-β⁺NK1.1⁻CD4⁺/CD8⁺), and NK1.1⁺TCR⁺ (NK1.1⁺TCR-β⁺) T cells. Data represent mean (SD) proportion of positive wells from 2 independent experiments, with 24 to 36 wells being analyzed in each experiment.