PGK1 and esophageal squamous cell carcinoma: To further cross-validate these results, our dataset confirmed that the expression of PGK1 was gradually increased in ESCC at the protein and phosphoprotein levels (Kruskal–Wallis test, FDR = 1.3E–18 for proteome and 4.2E–3 for phosphoproteome, stage 9 vs. stage 1 ratio = 2.30 for proteome and 2.49 for phosphoproteome) (Fig. 7c), as demonstrated by immunohistochemistry of ESCC FFPE slides in which PGK1 was gradually increased in the process from T0 stage (normal tissue) to the Tis stage, SM2 stage, and advanced stage (Fig. 7d).