GLS and esophageal squamous cell carcinoma: Spearman correlation analysis was used to investigate the expression levels of 12 CRGs (ATP7B, CDKN2A, DLAT, DLD, FDX1, GLS, LIAS, LIPT1, MTF1, PDHA1, PDHB, and SLC31A1) from the TCGA-ESCC cohort, and the results are presented in Figure 4C.