Kringle Containing Transmembrane Protein 2 is a high-affinity dickkopf homolog 1 (DKK1) transmembrane receptor. A similar protein in mouse functions interacts with with DKK1 to block wingless (WNT)/beta-catenin signaling. The encoded protein forms a ternary membrane complex with DKK1 and the WNT receptor lipoprotein receptor-related protein 6 (LRP6), and induces rapid endocytosis and removal of LRP6 from the plasma membrane. It contains extracellular kringle, WSC, and CUB domains.