The higher PSMD2 levels were more evident in advanced ESCC (III and IV stages) compared to those of early I and II stages (p < 0.0001; Fig. 2D), and were correlated with the poor prognosis of ESCC patients (p = 0.045 for the log-rank test; Fig. 2E). This evidence concerns the gene PSMD2 and esophageal squamous cell carcinoma.