TNFSF11 and Familial prostate cancer: Thus, prostate cancer cells ectopically express markers of bone, such as the bone formation transcription factor Runx2 or the bone resorption factor Receptor Activator of Nuclear Factor Kappa-β-Ligand (RANK-L) and behave as bone cells to adapt and grow in the bone microenvironment [6,7,8,9].