Pairwise comparison of infected to mock lung samples from adult or aged animals at different time points after infection using Ingenuity Pathway Analysis (IPA) confirmed that adult animals were mounting a rapid and well-orchestrated innate and adaptive immune response, characterized by the initiation of PRR signaling, NK cell activation, and the production and response to Th1/Th2 cytokines (Fig. 5 C). Here, NELFCD is linked to infection.