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