As IL-12 is a very important proinflammatory cytokine rapidly released by immune cells, for example, during infection, and the effect of MSC on NK cells in the IL-12-containing cytokine milieu has not been examined so far, we investigated the influence of bone marrow-derived MSC on the IL-12/IL-18-stimulated IFN-γ production of NK cells. Here, IFNG is linked to infection.