The same accounts for the glycoprotein olfactomedin 4 (OLFM4), up-regulated in both forms of IBD according to our data, that is secreted into mucus [22] and acts by inhibiting immune responses against Helicobacter pylori, hence contributing to the persistence of infection by a mechanism involving NOD1 and NOD2 [23]. Here, OLFM4 is linked to infection.