CD226 and infection: DNAM-1 is another activating receptor expressed by NK and CD8 T cells, in addition to distinct cell types, that recognizes two cell adhesion molecules (DNAM-1 ligands or DNAM-1Ls), CD155 (also referred to as poliovirus receptor-PVR or nectin-like molecule 5), and CD112 (nectin-2 or herpes entry mediator B-HVEB), which are generally up-modulated in response to various cellular stresses; hence, they can trigger cytotoxic responses against cells undergoing tumor transformation or infection [93].