 Examples of PAMPs include the peptidoglycan cell wall or LPS, both of which are essential components of bacteria and are therefore evolutionarily conserved across many different bacterial species.When a foreign pathogen bypasses the physical barriers and enters an organism, the PRRs on macrophages will recognize and bind to specific PAMPs.This binding results in the activation of a signalling pathway which allows for the transcription factor NF-κB to enter the nucleus of the macrophage and initiate the transcription and eventual secretion of various cytokines such as Il-8, Il-1, and TNFα.