The results showed that the expression levels of serum HMGB1 and IDO in ESCC group were significantly higher than those in control group (P<0.001) (Figures 1A, B), They had good value of auxiliary diagnosis in both the healthy people and ESCC patients (P<0.001) (Figure 1C). The gene discussed is HMGB1; the disease is esophageal squamous cell carcinoma.