GGTLC2 (gamma-glutamyltransferase light chain 2) is a light chain-encoding gene of the extended GGT family located on chromosome 22 1. While the canonical GGT1 functions as an extracellular enzyme critical for glutathione metabolism and leukotriene LTC4-to-LTD4 conversion 1, GGTLC2's specific enzymatic role remains uncharacterized 1. However, emerging evidence demonstrates significant disease relevance. GGTLC2 is highly expressed in gastric cancer (GC) and promotes tumor progression through ferroptosis inhibition, with upregulation associated with liver metastasis and poor prognosis 2. Functionally, GGTLC2 enriches in oxidative stress and immune pathways, modulating immune infiltration and inflammatory factor expression in the tumor microenvironment 2. GGTLC2 knockdown inhibits GC proliferation and migration while promoting apoptosis and ferroptosis, whereas overexpression increases hepatic metastatic burden 2. Beyond gastric cancer, GGTLC2 serves as a prognostic antioxidant gene signature component in sarcoma, predicting overall and disease-free survival 3. Additionally, GGTLC2 deletion at 22q11 occurs in ~15% of chr22 lymphocytic leukemia cases with reduced mRNA expression correlating with deletion status 4. These findings establish GGTLC2 as a promising biomarker for cancer diagnosis and prognosis across multiple malignancies.