SOST and uremia: In this context it should be noted that the plasma levels of the circulating Wnt inhibitors sclerosin (Sost) and dickkopf-related protein 1 (Dkk1) are increased in uremia [33] and advanced uremia might per se be associated with a general state of Wnt inhibition, which potentially could make pharmacological inhibition of Wnt signalling less efficient.