In vitro, WIF1 suppresses β-catenin expression in osteosarcoma cell lines and induces differentiation of primary human osteoblasts, and in primary human osteosarcoma samples, silencing of WIF1 is associated with increased proliferation, increased β-catenin expression, and loss of differentiation, implying that de-repression of Wnt signaling plays a positive role in osteosarcoma pathogenesis. Here, WIF1 is linked to osteosarcoma.