Objective To test the expression of IDO and VEGF m RNA in tumor tissues and para-carcinoma tissues of esophageal squamous cell carcinoma(ESCC)patients and to investigate their associations with tumor invasion and lymphatic metastasis. Methods Carcinoma tissue and para-carcinoma tissue specimens were collected from 56 cases of ESCC patients who underwent esophagectomy in The Fourth Hospital of Hebei Medical University. Optical density semi-quantitative RT-PCR and immunohistochemical method were used to detec...