SP7 and osteosarcoma: Some studies have also identified the cancer‐promoting effects of OSX in different types of cancers, including human osteosarcomas and prostate cancer.5, 6 Nevertheless, in a study based on a mouse osteosarcoma model, Osx was down‐regulated and its expression was negatively associated with metastatic potency.35 This discrepancy may be caused by the context dependence of the specific cell lines used in each study.