WIF1 and neoplasm: Other examples of tumor suppressor genes described as mutated in OS include the β-catenin regulatory protein APC (Adenomatous polyposis coli), the metalloproteinase inhibitor TIMP3 (Metalloproteinase inhibitor 3) and the Wnt pathway inhibitor WIF-1 (Wnt inhibitory factor 1) [78,92,93,94,95,96,97].