PVR and neoplasm: Several approaches that leverage CD155 interactions are under investigation, including recombinant oncolytic polioviruses (e.g., PVSRIPO) that selectively target tumor cells expressing CD155 (36, 37), checkpoint blockade therapies that inhibit receptors like TIGIT to restore immune function (38–40), and DNAM-1–based adoptive cell therapies designed to enhance immune cytotoxicity against CD155-expressing tumors (41, 42).