PVR and neuroblastoma: To evaluate the potential of NB cells to engage the NK cell activation or inhibitory receptors, we investigated the expression levels of the respective ligands, MHC class I chain-related protein A and B (MIC A/B), CD112, CD155, and human leukocyte antigen-ABC (HLA-ABC), in the NB cell lines SK-N-FI, Be2C, SK-N-DZ, and CHLA-255.