Furthermore, in mice experimental models lactobacilli elicited systemic effect such as antigen presenting cell migration, enhanced TNF-α and interferon production in airways in response to influenza infection [22, 40–42] Clinical trials evaluating the role of probiotics in respiratory viral infections have demonstrated a probiotic-dependent increase in serum concentration of interferon-γ, NK cell activity, Th1 cell activation, and an increased number of T-helper and T-killer cells [43–45]. The gene discussed is TNF; the disease is influenza.