Previous studies have shown that tumor cell-derived t-PA and u-PA could activate plasminogen to form plasmin, and then accelerate local invasion and distant metastasis of tumor cells [29–31]; T-PA and u-PA were also proved to be abnormally elevated in the plasma of patients with malignant tumor, and they were closely related to the resectability and shortened survival time [32, 33]. The gene discussed is PLG; the disease is cancer.