Toll like receptors (TLRs) are highly conserved proteins that are first known for their role in pathogen recognition and immune response activation. In order to elicit the necessary immune response in reaction to a foreign pathogen, TLRs trigger cytokine production depending on the behavior patterns of the pathogen itself. Specifically, TLR4 acts through bacterial lipopolysaccharide (LPS), which composes the outer wall of Gram-negative bacteria. Bacterial LPS is also a potent activator of the immune system.
