Apart from inducing angiogenesis and bypassing apoptosis by quenching TRAIL ligand, our study [6] for the first time demonstrated that OPG has the potential of reprogramming healthy human mammary epithelial spheres (HMEC), driving them towards tumorigenesis thus mimicking the scenario in breast cancer spheres (Figure 2). This evidence concerns the gene TNFRSF11B and breast carcinoma.