Comparison of HSPA2 mRNA and protein levels in ESCC samples, adjacent non-cancerous tissues and normal tissues by qRT-PCR and western blotting. (A) Relative HSPA2 mRNA expression levels in different tissues: cancer, 30 paired ESCC samples; adjacent, adjacent non-cancerous tissues; normal, normal esophageal tissues. (B) Relative HSPA2 mRNA expression levels in ESCC tissues at different stages: early and advanced. (C) Representative western blotting analysis of HSPA2 expression in all specimens. (D) Relative HSPA2 protein expression levels in different tissues. *P >0.05, compared with normal tissues; **P <0.05, compared with normal tissues and adjacent non-cancerous tissues. The relative HSPA2 protein expression level in ESCC tissues is about 2.67 times of that in normal esophageal tissues, and 2.35 times of that in adjacent non-cancerous tissues. Boxes represent the medians and interquartile ranges of the normalized threshold values. ESCC, esophageal squamous cell carcinoma; qRT-PCR, quantitative RT-PCR.