Denosumab, a receptor activator of nuclear factor kappa B (RANK) ligand inhibitor, was approved in 2011 in the EU for use in patients with solid tumours and bone metastases, after having demonstrated superiority versus zoledronic acid in patients with prostate cancer, breast cancer and other solid tumours in three large randomised clinical trials [21–24]. The gene discussed is TNFRSF11A; the disease is prostate cancer.