These findings strongly suggested the importance of the RANKL/RANK/OPG system in NSCLC bone metastasis, and encouraged us to examine the relationship between the expression levels of three components in the system and the various clinical features of NSCLC and to evaluate the potential of the RANKL/RANK/OPG system as a therapeutic target in the context of bone metastasis of NSCLC origin. The gene discussed is TNFSF11; the disease is non-small cell lung carcinoma.