The co-expression of glutaminase 1 (GLS1) and gamma-glutamylcyclotransferase (GGCT), constituents of glutamine metabolism, was strongly associated with histological grade, lymph node metastasis, and TNM stage III/IV of gastric cancer (Jiang et al., 2019a). This evidence concerns the gene GGCT and metastatic malignant neoplasm in the lymph nodes.