uPA is a serine protease of 55 kDa molecular mass, mainly composed of a growth factor-like domain, a kringle domain and a serine protease domain.[9] In the tumor progression, uPA binds to its cell surface receptor uPAR, which then catalyzes the further transformation of pro-metalloproteinases into metalloproteinases.[10] These activated metalloproteinases then promote the degradation of the extracellular matrix,[11] and contribute to tumor cell invasion and metastasis at secondary tumor sites. The gene discussed is PLAU; the disease is neoplasm.