Figure 3.

Human natural killer cell subsets based on CD56 and CD16 expressions: Around 90% of natural killer cells isolated from the blood display dim level of CD56 and high density of CD16 (CD56^dimCD16^bright).

Notes: These cells are more cytotoxic via perforin and granzyme secretion¹⁵ than natural killer cells showing bright expression of CD56 and no or low expression of CD16 (CD56^brightCD16^−/low). These latter cells produce more cytokines.¹⁶

Abbreviations: GM-CSF, granulocyte–macrophage colony-stimulating factor; IFN-γ, interferon γ; IL-10, interleukin 10; TNF-α, tumor necrosis factor α.