May act as a physical homophilic interaction molecule between intestinal epithelial cells (IECs) and intraepithelial lymphocytes (IELs) at the mucosal epithelium for providing immunological barrier as a first line of defense against mucosal infection. Plays a role in embryonic stem cells proliferation and differentiation. Up-regulates the expression of FABP5, MYC and cyclins A and E (By similarity). Monomer (By similarity). Interacts with phosphorylated CLDN7. Colocalizes with CLDN7 at the lateral cell membrane and tight junction. Glycosylation at Asn-198 is crucial for protein stability. Belongs to the EPCAM family.