IL4 and hemorrhagic fever with renal syndrome: Because HFRS is associated with a higher inflammatory response and many inflammatory cytokines and chemokines are involved in the process, our research team [36] evaluated the serum TNF-α, IL-6, IL-4, IL-8,interferon (IFN)-γ, IP-10, and chemokine (C–C motif) ligand 5 levels in HFRS patients.