Epithelial to mesenchymal transition (EMT) followed by loss of adhesion proteins (e.g., cadherins), degradation of the extracellular matrix (ECM) by matrix metalloproteinases (MMPs), cathepsins and the urokinase-type plasminogen activator (uPA) system, as well as co-option of factors from the tumor microenvironment to support metastasis (e.g., cytokines TGF-β and SDF1), are all processes that provide cancer cells with the ability to invade blood vessels and migrate to distant sites in the body. This evidence concerns the gene PLAU and cancer.