TFF1 and esophageal squamous cell carcinoma: We next analyzed TFF1 expression levels in the same sample groups and found a lower expression of TFF1 in ESCC and histologically normal surrounding tissue (median of 5 × 10−4 and 4.3 × 10−4, respectively) when compared with healthy esophageal epithelium (median of 2.8 × 10−3, Fig. 1a).