Dickkopf-related protein 2 is a member of the dickkopf family. The secreted protein contains two cysteine rich regions and is involved in embryonic development through its interactions with the Wnt signaling pathway. It can act as either an agonist or antagonist of Wnt/beta-catenin signaling, depending on the cellular context and the presence of the co-factor kremen 2. Activity of this protein is also modulated by binding to the Wnt co-receptor LDL-receptor related protein 6 (LRP6).Northern blot analysis revealed expression of 4.0- and 4.5-kb DKK2 transcripts in heart, brain, skeletal muscle, and lung. Western blot analysis showed that DKK2 is secreted as a 15- to 17-kD protein. Functional analysis determined that DKK2 does not block Xenopus Wnt8 induction of a secondary axis in frog embryos.