TNF and asthma: The serum samples of these mice also had lower IL-1β (all P < 0.05), TNF-α (all P < 0.05), IL-4 (all P < 0.05) and IL-5 (all P < 0.05) levels and higher levels of IFN-γ (P < 0.001) compared with the OVA-induced asthma mouse model.