IAP is a type of glycoprotein anchored in the apical membrane of intestine by a glycosyl-phosphatidyl-inositol linkage, which plays an important role in gut barrier function, including detoxification of bacterial LPS and free nucleotides [49,50], remission of intestinal inflammation [27,51], and modulation of gut microbiota [52,53,54,55]. Here, ART4 is linked to inflammation.