TNFSF11 and neoplasm: Once in the bone, tumor cells promote the secretion of various cytokines such as RANKL, Vascular endothelial growth factor (VEGF), Interleukin-1 (IL-1), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-11 (IL-11) and Tumor necrosis factor-α (TNF-α) directly or indirectly, which induces the formation and maturation of osteoclasts resulting in massive bone absorption, which provides favorable conditions for tumor cell colonization (8).