Three activating receptors found on NK cells, NKp30, NKp44, and NKp46, are collectively known as Natural Cytotoxicity Receptors (NCRs). These receptors are crucial in NK cells antitumor and antiviral defenses. p46, a novel natural killer cell-specific surface molecule that mediates cell activation. NKp46 has been established as a critical activating receptor since it is expressed almost exclusively by NK cells and is the only NCR with a mouse orthologue. Its ligand repertoire ranges from viral ligands.