TNFSF11 and neoplasm: We demonstrated metastatic specific mesenchymal stromal cells (MSCs) that appear to have the capacity to promote epithelial-to mesenchymal transition (EMT) in tumor cells and that are accompanied by a phenotype of bone remodeling driven by dysregulation of RANK (TNFRSF11A)-RANKL (TNFSF11) and Osteoprotegerin (OPG, TNFRSF11B) signaling.