DKK1 and hyperostosis corticalis generalisata: Nevertheless, patients with sclerostin deficiency (sclerosteosis and van Buchem disease) show increased bone formation despite significantly higher DKK1 plasma levels (van Lierop et al. 2014), which suggests an adaptative response to increased bone formation characterizing these diseases although high DKK1 levels do not compensate for the lack of sclerostin.