Involved in the cell-cell adhesion. Has both calcium-independent homophilic cell-cell adhesion activity and calcium-independent heterophilic cell-cell adhesion activity with IGSF4, NECTIN1 and NECTIN3. Interaction with EPB41L1 may regulate structure or function of cell-cell junctions. Homodimer. Can form trans-heterodimers with NECTIN3. Interacts with EPB41L1, DLG3, PALS2 and CASK. Mainly expressed in brain, in neuronal cell bodies of cerebellum, cortex, hippocampus, hypothalamus and spinal cord. In spinal cord predominantly expressed in motor neurons. Expressed in axons, presynaptic nerve terminals, glia cell processes. At 14.5 dpc predominantly expressed in the nervous system. The cytoplasmic region mediates interaction with EPB41L1, DLG3, PALS2 and CASK. Belongs to the nectin family.