Decoy receptor 3 (DcR3), also called TNFRSF6B, TR6 and M68, is a member of the TNF receptor superfamily. DcR3 lacks a transmembrane sequence and is a secreted protein. DcR3 shares sequence identity with OPG (31%), TNF RII (29%) and Fas (17%), and is expressed in a variety of different tissues and at high levels in many malignant tumors.