Serum CDC25B-Abs were detected in a higher proportion of patients with ESCC than healthy control subjects (P < 0.001, Figure 2A); however, sera from only 17.2% of ESCC patients contained SCC-Ag at levels above the cut-off value of 1.5 ng/ml, 13.4% of ESCC patients contained CEA at levels above the cut-off value of 5.0 ng/ml and 32.1% of ESCC patients with the sera CYFRA21-1 levels above the cut-off value of 3.5 ng/ml. This evidence concerns the gene CDC25B and esophageal squamous cell carcinoma.