It is composed of two extracellular Ig-like domains, and is a member of both the immunoglobulin superfamily and the multi-chain immune recognition receptor (MIRR) family.
Está composto por dous dominios similares a Ig extracelulares, e é membro tanto da superfamilia das inmunoglobulinas coma da familia do receptor de recoñecemento inmune multicadea (MIRR).