DAP12 (KARAP) is a natural killer (NK) cell-expressed cell surface receptor and belongs to the immunoglobulin and C-type lectin superfamily. Unlike other members of this family which possess immunoreceptor tyrosine-based inhibitory motifs (ITIM), DAP12 contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain and is present as a disulphide-bonded homodimer. Crosslinking of DAP 12-KIR complexes (membrane glycoproteins of the killer-cell inhibitory receptor family without an ITIM in their cytoplasmic domain) results in cellular activation.