DKK3 and osteosarcoma: Contradictory to this, Dkk3 is reported to function as an inhibitor of Wnt signaling, either by associating with bTrCP and blocking β–catenin from entering the nucleus (as seen in HeLa cells) [38], or by increasing the localisation of β–catenin in the cell membrane, as seen in osteosarcoma cells [21].