PVR (Poliovirus Receptor): PVR is a transmembrane glycoprotein that acts as a receptor for poliovirus and related enteroviruses, enabling viral entry and infection. Beyond its role in viral recognition, PVR is crucial for cell-to-cell adhesion, immune regulation, and tissue homeostasis. It supports the integrity of epithelial and endothelial barriers through its participation in adherens and tight junctions. Interactions between PVR and ligands such as TIGIT and DNAM-1 help regulate immune cell activation, affecting both innate and adaptive immune responses. Dysregulation of PVR expression or function can significantly impact immune function and tissue integrity.