Objective        To determine the expression of  transcription factor FoxO1

and its correlations to the clinicopathological features of esophageal squamous cell carcinoma（ESCC）．      Methods       SYBR green real-time fluorescent quantitative reverse transcriptase PCR was used to detect the expression levels of FoxO1 mRNA in 42 matched pairs of ESCC tissues and normal samples. The protein expression and location of FoxO1 were measured by immunohistochemistry （SP method）．The expression was analyzed with gender

age

site

TNM stage

lymphatic metastasis

and tumor cell differentiation.       Results        The expression of FoxO1 at mRNA or protein levels was upregulated significantly in ESCC tissues compared with normal esophageal epithelium tissues (P0.01）. The expression of FoxO1 was higher in well differentiated ESCC than in poorly differentiated ESCC and normal esophageal epithelium tissues (P0.01）. However

the expression of FoxO1 was not correlated to clinicopathological characters

such as gender

age

tumor site

TNM stage

lymphatic metastases and tumor cell differentiation （P0.05）．The protein expression of FoxO1 was consistent with that of its mRNA expression．      Conclusion        The expression of FoxO1 varies significantly in ESCC and normal esophageal epithelium tissues．Over-expression of FoxO1 is closely related to the differentiation of ESCC．