SALL4 and esophageal squamous cell carcinoma: To assess the biological functional role of SALL4 in ESCC, we further explored the expression of SALL4 in an immortalized esophageal epithelial cell line (Het1A) and 7 ESCC cell lines (TE1, TE7, EC1, EC109, EC9706, KYSE70 and KYSE450) by real-time PCR (Fig. 2a).