Understanding Glutathione: The Master Antioxidant Bliss Welness Gamma glutamyl transferase (GGT) is an enzyme primarily found in the liver, bile ducts, and kidneys. It plays a key role in glutathione metabolism by facilitating the transfer of gamma glutamyl groups, which Genetic mapping of renal glutathione suggests a novel regulatory locus on the murine X chromosome and overlap with hepatic glutathione regulation ScienceDirect Genomics and the Kidney Basicmedical Key