Component of the epithelial apical junction complex that may function as a homophilic cell adhesion molecule and is essential for tight junction integrity. Also involved in transepithelial migration of leukocytes through adhesive interactions with JAML a transmembrane protein of the plasma membrane of leukocytes. The interaction between both receptors also mediates the activation of gamma-delta T-cells, a subpopulation of T-cells residing in epithelia and involved in tissue homeostasis and repair. Upon epithelial CXADR-binding, JAML induces downstream cell signaling events in gamma-delta T-cells through PI3-kinase and MAP kinases. It results in proliferation and production of cytokines and growth factors by T-cells that in turn stimulate epithelial tissues repair (By similarity). Monomer. May form homodimer. Interacts with LNX, MAGI1, DLG4, PRKCABP, TJP1 and CTNNB1. Interacts with MPDZ; recruits MPDZ to intercellular contact sites. Interacts with JAML (homodimeric form) (By similarity). In epithelial cells localizes to the apical junction complex composed of tight and adherens junctions. In airway epithelial cells localized to basolateral membrane but not to apical surface. The Ig-like C2-type 1 domain mediates homodimerization and interaction with JAML. The PDZ-binding motif mediates interaction with MPDZ and MAGI1. N-glycosylated. Palmitoylated on Cys-259 and/or Cys-260; required for proper localization to the plasma membrane.