– Dickkopf-related protein 3 (DKK3) belongs to the DKK protein family including Dkk-1, 2, 3 and -4. DKK3 is a 350 amino acid secreted glycoprotein which is comprised of an N-terminal signal peptide and 2 conserved cysteine-rich domains that are separated by a 12 amino acid linker region. Dkk-3 also have one prokineticin domain. DKK3 is involved in embryonic development through its inhibition of the WNT signaling pathway. The Dkk family also includes Soggy, which is homologous to Dkk-3 but not to the other family members. Soggy has not been shown to inhibit Wnt signaling, and its role in the pathway is unclear.