Overall survival and disease-free survival curves constructed by Kaplan-Meier analysis, grouped by HSPA2 expression (negative expression, positive expression). (A) Overall survival and (B) disease-free survival curves. Log-rank test (A: χ2 = 16.180, P <0.001; B: χ2 = 18.149, P <0.001) demonstrated that ESCC patients in the HSPA2-positive expression group had shorter overall survival and poorer disease-free survival compared with those in the HSPA2-negative expression group. Three patients were lost to follow-up because of telephone number changes or home moving. ESCC, esophageal squamous cell carcinoma.