In this study, immunohistochemistry (IHC) results of triple samples of 60 patients with ESCC showed that the significant higher expression level of GPX2 protein was detected in ESCC tumour tissues compared with non-tumour including PN and DN tissues (P < 0.001) (Fig. 2a and b). The gene discussed is GPX2; the disease is esophageal squamous cell carcinoma.