Knockdown of STIP1 by specific shRNAs in the OS-RC-2-BM5 cells led to a more than 50% inhibition of cell proliferation, and patients with low STIP1 expression also showed less Ki67-positive proliferating tumor cells in their bone metastatic lesions, suggesting the pro-proliferation role of STIP1 on the bone-seeking cells. This evidence concerns the gene MKI67 and neoplasm.