FGA and infection: Accordingly, NK1.1 expressed in NK cells, NKT cells and ILC1 cells, as well as NKp46 and granzyme, were upregulated in the lungs of infected Fga−/− and Fggγ390–396A mice (Fig. 2e and Extended Data Fig. 6a), suggesting a role for fibrin as a regulator of NK cells in infection.