APP including serum amyloid A, haptoglobin, alpha-1-acid glycoprotein, alpha-1-proteinase inhibitor (alpha-1-antitrypsin) and ITIH4 have been shown to increase in different inflammatory processes, in both in vivo and in vitro models, and involved several inflammatory diseases, such as Crohn’s disease and ulcerative colitis [39–41]. Here, ITIH4 is linked to Crohn disease.