Increased concentrations of lipopolysaccharides and fMLP in the blood has also been shown with in vitro studies to inhibit chemotaxis towards intermediate attractants such as IL-8, by down-regulating or desensitizing the IL-8 receptor by receptor phosphorylation, resulting in a possible reduced influx of neutrophils to sites of infection (8,28). This evidence concerns the gene FPR1 and infection.