Figure 7: Proteins specific for the gastrointestinal tract (GI-tract). Examples of proteins expressed in the group of gastrointestinal tissues. The examples include known GI-tract specific proteins such as the clinically used marker for GI-tract tumours Keratin-20 (A) and CDH17, a member of the cadherin super family of calcium-dependent, membrane-associated glycoprotein’s, showing membranous expression in normal colonic crypts (B). Several proteins expressed in mucus producing glandular cells were in the top 100 list, including MUC5B showing expression in goblet cells of the rectal mucosa (C). The unknown protein encoded by C1ORF201 showed a diffuse cytoplasmic expression pattern in the small intestine (D).