Figure 1: Simplified figure of selected bone-targeted therapies in mCRPC and their targets. Zoledronic acid binds to hydroxyapatite crystals preventing the activity of osteoclasts and stimulating osteoblast. Denosumab binds to RANKL preventing the binding of RANKL to RANK thus inhibiting activation of osteoclasts. Radiopharmaceuticals emit α or β ionizing radiation to the tumor cell in the bone.