Thus, it can be speculated that serum GGT has the potential to become a general biomarker of the tumor burden in patients with GU cancer, given that tumors arising from the urogenital organs overexpress GGT [46], possibly leading to its release into the bloodstream and its presence in the serum of patients with a metastatic disease in particular. The gene discussed is GGT1; the disease is metastatic neoplasm.