Nectins are a small family of Ca -independent immunoglobulin (Ig)-like cell adhesion molecules (CAMs) that organize intercellular junctions. They are highly homologous to the human receptor for poliovirus, and as such have been alternately named poliovirus receptor-related proteins.Nectin-1 promotes cell-cell contacts by forming homophilic or heterophilic trans-dimers. Heterophilic interactions have been detected between Nectin-1 and Nectin-3 and between Nectin-1 and Nectin-4. Has some neurite outgrowth-promoting activity.