TLR4 and neoplasm: As a type I transmembrane glycoprotein receptor containing 839 amino acids [30], TLR4 is widely expressed on various immune cells, epithelial/endothelial cells and tumor cells, etc. [31] Several auxiliary molecules including LPS binding protein (LBP), cluster of differentiation 14 (CD14), and myeloid differentiation factor 2 (MD-2) are required in the TLR4 receptor complex as co-receptors for TLR4 [31].