The cynomolgus monkey Dickkopf-4 (cDkk-4) protein, isolated nucleic acid molecules which encode the cDkk-4 protein, and recombinant vectors and hosts comprising DNA encoding the cDkk-4 protein are disclosed. Also disclosed are methods for identifying analytes which interfere with the interaction between the cDkk-4 protein and a homologous or heterologous Dkk receptor and analytes which interfere with the interaction and stimulate bone formation. Analytes identified using the methods are useful for treating osteoporosis and other bone loss disorders.