Poliovirus Receptor (PVR) is a 70 kDa type I transmembrane single-span glycoprotein that belongs to the nectin-like (Necl) family and was originally identified based on its ability to mediate the cell attachment and entry of poliovirus (PV); an etiologic agent of the central nervous system disease poliomyelitis. PVR contains three Ig-like extracellular domains; a transmembrane segment; and a cytoplasmic tail. The normal cellular function of PVR maybe the involvement of intercellular adhension between epithelial cells. Alternate splicing of the PVR mRNA yields four different isoforms (α; β; γ; and δ) with identical extracellular domains.