Cluster of Differentiation 112 (CD112), also known as poliovirus receptor related protein 2 (PVRL2 or PRR2), is a single-pass type I transmembrane glycoprotein belonging to the Immunoglobulin superfamily. CD112 protein also serves as an entry for certain mutant strains of herpes simplex virus and pseudorabies virus, and thus is involved in cell to cell spreading of these viruses. CD112 protein has been identified as the ligand for DNAM-1 (CD226), and the interaction of CD226/CD112 protein can induce NK cell- and CD8+ T cell-mediated cytotoxicity and cytokine secretion. CD112 has been regarded as a critical component in allergic reactions, and accordingly may function as a novel target for anti-allergic therapy.