GGT1 (gamma-glutamyltransferase 1) is a membrane-associated enzyme involved in glutathione metabolism and redox homeostasis. While UniProt suggests catalytic inactivity, structural studies reveal an active site capable of binding and processing glutathione substrates, with key interactions at the cysteinylglycine binding site 1. GGT1 functions in glutathione catabolism and participates in amino acid metabolism, supporting L-cysteine biosynthesis and leukotriene metabolism. Mechanistically, GGT1 acts as a ferroptosis resistance factor in cancer cells. In triple-negative breast cancer, hepatic leukemia factor transactivates GGT1 to promote ferroptosis resistance, driving cell proliferation, metastasis, and cisplatin resistance 2. GGT1 also associates directly with gp130 and regulates IL-6-mediated STAT3 activation, functioning as a positive regulator of the IL-6 amplifier 3. GGT1 polymorphisms associate with multiple diseases. Genetic variants influence susceptibility to post-ERCP pancreatitis through STAT3 pathway activation 3, ischemic stroke risk (with protective effects in non-smokers and non-alcohol abusers) 4, and neoadjuvant chemotherapy response and toxicity in breast cancer 5. GGT1 is also identified as a glutamine metabolism-related gene in diabetic foot ulcer pathogenesis 6. These findings suggest GGT1 as a therapeutic target in cancer, inflammatory, and metabolic diseases.