TNF and viral infectious disease: The chorion cells may produce MCP-1, IP-10, RANTES, and MIP-1β to recruit maternal circulating monocyte and IL-6, TNF-α, and IFN-β to differentiate the recruited maternal monocytes and the staying fetal amnion mesenchymal cells [80] to macrophages as scavengers for huge numbers of corpses of neutrophils and massive number of corpses of chorion cell themselves resulting from apoptosis induced by the virus infection.