S100A9 and juvenile polyposis syndrome: Several blood-based biomarkers have been identified in recent years as being of value for the diagnosis of PJI, including soluble intercellular adhesion molecule-1 (sICAM-1), myeloid-related protein 14 (MRP-14), soluble urokinase plasminogen activation receptor (su-PAR), and lipopolysaccharide-binding protein (LBP).