Poliovirus receptor-related 3 (PVRL3), also known as Nectin-3 and CD113, is a member of the nectin family. PVRL3/Nectin-3 is an 83 kDa, type I transmembrane glycoprotein. Its precursor is 549 amino acids (aa) in length and contains an extended signal sequence of 57 aa, an extracellular domain (ECD) of 347 aa, a transmembrane segment of 21 aa, and a cytoplasmic region of 124 aa. Nectin-3 has three splicing variants, nectin-3alpha (biggest), -3beta (middle), and -3gamma (smallest). It is predominantly expressed in testis and placenta as well as in various cell lines, including epithelial cell lines. PVRL3/Nectin-3 plays a role in cell-cell adhesion through heterophilic trans-interactions with nectin-like proteins or nectins, such as trans-interaction with PVRL2/Nectin-2 at Sertoli-spermatid junctions. PVRL3/Nectin-3 is thus involved in the formation of cell-cell junctions, including adherens junctions and synapses. It has been shown to induce endocytosis-mediated down-regulation of PVR from the cell surface, resulting in reduction of cell movement and proliferation.