Collectively, these results demonstrate that DFCs robustly enhance RANKL and PTHrP expression in OSCC cells at bone-invasion sites, thereby amplifying osteoclast-activating signals, whereas PDLCs exert the opposite effect—sharply down-regulating RANKL while limiting the overall PTHrP output, despite a relative enrichment of PTHrP-positive cancer cells. This evidence concerns the gene TNFSF11 and cancer.