To determine the critical effect of tumor-derived PTHrP on NKX2-8 silencing-mediated osteoclastogenesis, the osteoclast precursor cells was treated with three types of PTHrP inhibitors, including the peptide antagonist PTHrP7–34, the neutralizing antibody and the chemical inhibitor 6-thioguanine (6-TG), under conditions of CM from NKX2-8-silenced cells. This evidence concerns the gene NKX2-8 and neoplasm.