TNFSF11 and lung cancer: Other findings that substantiated the role of RANKL-RANK in lung cancer progression and bone metastasis include (i) the demonstration that RANKL was effective in triggering the migration in human cancer cells that express RANK [32] and (ii) RANK-Fc (a recombinant soluble protein consisting of extracellular domain of RANK coupled with the Fc domain of human IgG) was effective in inhibiting the RANK-RANKL interaction, thereby preventing osteoclastogenesis [37].