TNF and infection: Analysis of mouse bronchial alveolar fluids indicated that MDk/W452(H5N8) infection moderately upregulated the expression of cytokines/chemokines, whereas the HPAI A(H5N1) viruses, particularly EM/W149(H5N1), induced robust expression of all the pro-inflammatory cytokines/chemokines, including tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, regulated on activation, normal T cell expressed and secreted (RANTES), and granulocyte macrophage colony-stimulating factor (GM-CSF).