Mediates NK cell adhesion and triggers NK cell effector functions. Binds two different NK cell receptors: CD96 and CD226. These interactions accumulates at the cell-cell contact site, leading to the formation of a mature immunological synapse between NK cell and target cell. This may trigger adhesion and secretion of lytic granules and IFN-gamma and activate cytotoxicity of activated NK cells. May also promote NK cell-target cell modular exchange, and PVR transfer to the NK cell. This transfer is more important in some tumor cells expressing a lot of PVR, and may trigger fratricide NK cell activation, providing tumors with a mechanism of immunoevasion. Plays a role in mediating tumor cell invasion and migration. {ECO:0000269|PubMed:15471548, ECO:0000269|PubMed:15607800}. (Microbial infection) Acts as a receptor for poliovirus. May play a role in axonal transport of poliovirus, by targeting virion-PVR- containing endocytic vesicles to the microtubular network through interaction with DYNLT1. This interaction would drive the virus- containing vesicle to the axonal retrograde transport. . (Microbial infection) Acts as a receptor for Pseudorabies virus. . (Microbial infection) Is prevented to reach cell surface upon infection by Human cytomegalovirus /HHV-5, presumably to escape immune recognition of infected cell by NK cells. . This is the function of PVR (PVR cell adhesion molecule, Ensembl gene identifier ENSG00000073008).