TNFSF11 and neoplasm: To this, the transforming growth factor-β (TGF-β), the parathyroid hormone-related peptide (PTHrP), the receptor activator of nuclear factor kappa-B ligand (RANKL) as well as the interleukin (IL)-6 have been proven to be variably enrolled in favouring the tumor cell seeding within the pre-metastatic niche as well as metastasis development [5–8].