DKK3, also known as dickkopf WNT signaling pathway inhibitor 3, is a member of the DKK protein family including Dkk-1, 2, 3 and 4. It is a secreted protein with two cysteine rich regions and is involved in embryonic development through its inhibition of the WNT signaling pathway. The expression of this gene is decreased in a variety of cancer cell lines and it may function as a tumor suppressor gene. Recombinant human DKK3 protein, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.