Figure 1: Schematic overview of toll-like receptor 4 downstream signaling pathway. Toll-like receptor 4 ligands bind to toll-like receptor 4 on the cell membrane, leading to the activation of myeloid differentiation factor 88 signaling pathway. The myeloid differentiation factor 88 pathway signals through activation mitogen activated protein kinase and phosphoinositide 3-kinase signaling, which in turn leads to regulation of transcription factors nuclear factor-κB and activator protein-1, respectively, and mediates the inflammatory cytokines secretion.