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 (By similarity). Homodimer. Can form trans-heterodimers with NECTIN3. Interacts with EPB41L1, DLG3, PALS2 and CASK (By similarity). Isoform 1 is expressed mainly in adult and fetal brain. Isoform 2 is highly expressed in adult brain and weakly expressed in placenta. In brain, Isoform 2 is highly expressed in cerebellum. Markedly in glioma cell lines and prostate cancer cell lines. The cytoplasmic region mediates interaction with EPB41L1, DLG3, PALS2 and CASK. The disease is caused by variants affecting the gene represented in this entry. Belongs to the nectin family.