To determine whether ESCC cells express TRAIL, we examined TRAIL expression in seven human ESCC cell lines at different stages of differentiation ( KYSE150, KYSE70, EC1, EC109, EC9706, TE1 and TE-7) and normal esophageal epithelial cell line (HET-1α) at the mRNA and protein levels (Fig. 2a). This evidence concerns the gene TNFSF10 and esophageal squamous cell carcinoma.