In this model, NK cells are recruited to the lungs within a few days of infection and promote the development of adaptive type 1 immunity.38,39 We detected no differences in viral load in klrk1−/− mice, as measured by copies of viral L-gene at 4 days after infection, the peak of viral load in this model (see Fig E3, A in this article’s Online Repository at www.jacionline.org). Here, KLRK1 is linked to infection.