Poliovirus oncolytic immunotherapy is a putatively novel approach to treat pediatric brain tumors. This work sought to determine expression of the poliovirus receptor (PVR), CD155, in low-grade and malignant pediatric brain tumors and its ability to infect, propagate, and inhibit cell proliferation. CD155 expression in pleomorphic xanthoastrocytoma (PXA), medulloblastoma, atypical teratoid rhabdoid tumor, primitive neuroectodermal tumor, and anaplastic ependymoma specimens was assessed. The ability of the polio: rhinovirus recombinant, PVSRIPO, to infect PXA (645 [BRAF V600E mutation], 2363) and medulloblastoma (D283, D341) cells were determined by viral propagation measurement and cell proliferation. PVR mRNA expression was evaluated in 763 medulloblastoma and