Granulocyte migration through the gut wall into the feces allows determination of fecal S100A8/A9 in patients with inflammatory bowel diseases like Crohn's disease or appendicitis whereas release of S100A8/A9 by endothelial cells could be observed due to leukocyte interaction [26, 27, 37, 38]. The gene discussed is S100A8; the disease is appendicitis.