Presents a study which showed that low density lipoprotein-receptor-related protein 6 (LRP 6) is a specific, high-affinity receptor for extracellular Wnt inhibitors dickkopf1 (Dkk1) and dickkopf2. Method used to show the interaction between LRP6 and Dkk1; Characteristics of the dkk1 action during early Xenopus embryogenesis.