During infection, TLR4 specifically recognizes endotoxin lipopolysaccharide (LPS), a primary component of Gram-negative bacteria, which induces immune cells such as macrophages and neutrophils to produce many pro-inflammatory cytokines, including interleukin (IL)-8, IL-6, IL-1β and IL-12 and tumor necrosis factor α (TNFα), to eliminate the invading pathogens (Ramachandran, 2014). The gene discussed is TLR4; the disease is infection.