DKK1 and plasma cell myeloma: These proteins compete for the same Wnt signaling receptors, suppressing the differentiation and function of osteoblasts.354–358 Studies conducted both in vitro and in vivo have demonstrated that blocking DKK1 and augmenting Wnt signaling can restore the quantity of osteoblasts and trabecular bone, along with a reduction in tumor burden.359–362 After treating myeloma murines in vivo with a SOST-neutralizing antibody, results indicated a decrease in bone loss and lytic lesions, although there was no impact on tumor burden.363