Fig. 1

Study profile. ESCC, esophageal squamous cell carcinoma; ELISA, enzyme-linked immunosorbent assay; SUMC, Shantou University Medical College; SYSU, Sun Yat-sen University; CAMS & PUMC, Chinese Academy of Medical Sciences and Peking Union Medical College; AUC, area under the receiver operating characteristic curve; K-S value, Kolmogorov–Smirnov test; PSI, Population Stability Index