Quantitative analysis showed that the ODC immunostaining integrative optical density (IOD) value was 2255 ± 115 for ESCC, which was significantly higher than the value for esophagitis (1187 ± 236, p < 0.01) or NAT (888 ± 140, p < 0.01; Fig. 1a). This evidence concerns the gene BRD2 and esophageal squamous cell carcinoma.