ODC is associated with cell growth, proliferation, and transformation, and is overexpressed in various solid cancers. Moreover, a correlation between polyamine level and tumor stage is well established in colorectal cancers.22 One group previously showed the tumor:normal ratio of ODC mRNA expression in stage III and IV ESCC specimens is significantly higher than in stage I and II ESCC specimens (p = 0.043).24 In the present study, we disclosed the expression pattern of ODC in human ESCC. ODC immunostaining was observed in both the nucleus and cytoplasm (Fig. 1), which agrees with a previous report.25 The expression of ODC was at least twice as high in ESCC compared to esophagitis or NAT (Fig. 1a). Clinically, the expression level of ODC in ESCC was significantly correlated with lymph node metastasis status and TNM stage but not with either age or gender, indicating that ODC might also function as an oncogene in ESCC.