Like Toll-like receptor 4 (TLR4) in Toll-like receptor signaling pathway, it is an innate immune receptor on the cell surface that recognizes pathogen-associated molecular pattern (PAMP), including viral proteins, and triggers the production of type I interferon and pro-inflammatory cytokines to fight infection (de Kleijn and Pasterkamp, 2003). The gene discussed is TLR4; the disease is infection.