S100A9 and colitis: Because IECs are able to express IL-6Rα on the basal surface, and the ligation of IL-6Rαactivates nuclear factor kappa B (NF-κB) [41], [42], we investigated whether IL-6, which is abundantly expressed in the inflamed colon, modulates the expression of S100A9 in colonic epithelial cells (CECs) using an experimental colitis model.