PI3 and esophageal squamous cell carcinoma: To examine tumor tissue elafin expression in 63 ESCC patients with stage I–IIIA, we found that the elafin expression levels were higher in the tumor tissues than in their adjacent normal tissues (1.72 ± 0.97 vs. 1.17 ± 0.52; p < 0.0001, Figure S3; Table S2).