TNF and rheumatoid arthritis: In response to K562 target cell interaction, NK cells from stable remission exhibited reduced proportions of polyfunctional CD107a+IFN-γ+TNF-α+ subsets (Figure 4G), while proportions of CD107a+IFN-γ–TNF-α– subsets where significantly increased (Figure 4H), indicating that NK cells from patients with RA in remission gained a specific functional subset with an intact ability to degranulate in the absence of proinflammatory cytokine expression.