Dickkopf-related protein 1 is a protein that in humans is encoded by the DKK1 gene.This gene encodes a protein that is a member of the dickkopf family. It is a secreted protein with two cysteine rich regions and is involved in embryonic development through its inhibition of the Wnt signaling pathway. Dickkopf WNT signaling pathway inhibitor 1 (Dkk1) is a protein-coding gene that acts from the anterior visceral endoderm. The dickkopf protein encoded by DKK1 is an antagonist of the Wnt/β-catenin signalling pathway that acts by isolating the LRP6 co-receptor so that it cannot aid in activating the WNT signaling pathway. DKK1 was also demonstrated to antagonize the Wnt/β-catenin pathway via a reduction in β-catenin and an increase in OCT4 expression. This inhibition plays a key role in heart, head and forelimb development during anterior morphogenesis of the embryo.