Representative examples of CD107 expression on CD3- lung NK cells in uninfected controls and at 1, 3 and 5 dpi show that CD107 is only expressed at CD3- cell that do not express CD8α (Fig. 5A)Immediately after infection, the proportion of activated lung NK cells temporarily increased from 10.9 ± 0.9% in uninfected controls to 18.3 ± 2.5% at 1 dpi (p < 0.05). Here, CD8A is linked to infection.