Moreover, we demonstrated that PATZ1 negatively regulates the expression of proteinases such as uPA and MMPs that are important for the degradation of the ECM in normal follicular epithelial cells and thyroid cancer cells and that the transition to malignant phenotype induced by loss of nuclear PATZ1 is partly attributed to the promotion of cellular migration and invasion activity by upregulation of these proteinases in thyroid follicular epithelial cells. The gene discussed is PLAU; the disease is thyroid cancer.