CD200R3, also known as CD200RLb and OX-2 Receptor 3, is a disulfide-linked dimeric CD200R-like receptor which belongs to immunoglobulin superfamily. Its positively charged amino acid lysine associates with ITAM- or YxxM motif-bearing adaptor molecules such as DAP12, DAP10, FcRγ, and CD3ζ. CD200R3 functions as an activating receptor to regulate IgE independent immune response.