Receptor for Dickkopf proteins. Cooperates with DKK1/2 to inhibit Wnt/beta-catenin signaling by promoting the endocytosis of Wnt receptors LRP5 and LRP6 (PubMed:12050670). Plays a role in limb development; attenuates Wnt signaling in the developing limb to allow normal limb patterning and can also negatively regulate bone formation (PubMed:18505822). Interacts with ERLEC1 (PubMed:16531414). Forms a ternary complex with DKK1 and LRP6 (PubMed:12050670). Expressed in the developing brain and developing limb buds. Binding to ERLEC1 is mediated by the oligosaccharides linked to the kringle domain. Animals with a double knockout of KREM1 and KREM2 exhibit enhanced Wnt signaling accompanied by ectopic postaxial forelimb digits and expanded apical ectodermal ridges. They also exhibit increased bone volume and bone formation rates. Triple knockout mice KREM1/KREM2/DKK1 exhibit enhanced growth of ectopic digits.