Romosozumab, a monoclonal antibody that binds sclerostin, an inhibitor of the Wnt pathway is already tested in phase 3 studies for osteoporosis therapy, showing a good safety profile.71 The fact that BHQ880, an antiDkk-1 mAb, was well-tolerated in a phase Ib study in patients with relapsed or refractory multiple myeloma and prior skeletal-related events is encouraging for the safety of Dkk-1 inhibition.72 A phase I study evaluating safety and tolerability of an anti-Dkk-1 mAb(RN564) in women with osteopenia and healthy men has been completed and the results are expected.73 This evidence concerns the gene SOST and osteoporosis.