CD7⁺CD56⁺ NK cells, but not CD7^negCD56⁺ cells, produce IFNγ in response to K562 target cells or IL-12 + IL-18 stimulation. (A) Intracellular cytokine flow cytometry was performed on total PBMCs after no stimulation or stimulation with K562 target cells or IL-12 + IL-18. CD3/14/19^neg cells were gated for CD56 expression. These CD56⁺ cells were analyzed for IFNγ and CD107a expression in the CD7⁺ and CD7^neg fractions. Only CD7⁺CD56⁺ NK cells expressed IFNγ and CD107a after stimulation. One representative example of 6 are shown for IFNγ and CD107a expression. (B) CD7⁺CD56⁺ NK cells and CD7^negCD56⁺ monocyte/DC-like cells were sorted by flow cytometry and 1000 of each cell type were plated per well of a precoated anti-IFNγ ELISPOT plate. Cells were cultured either in media alone (not stimulated) or were stimulated overnight with K562 target cells or IL-12 + IL-18. One representative example of 3 experiments is shown.