and C. perfringens co-infection was highly correlated with IFN-α, IFN-γ, IL-4, IL-13, IL-16, LITAF, TGF-β4 and TNFSF15 in the jejunum, indicating that Th2 type cytokines mainly participated in avian NE. The gene discussed is TNFSF15; the disease is coinfection.