TFPI2 and esophageal squamous cell carcinoma: In this study, 4 out of 65 candidate tumor suppressor genes (ADHFE1, EOMES, SALL1, TFPI2) were found to be hyper-methylated in ESCC tissues while hypo-methylated in the adjacent control tissues as well as the peripheral blood samples, and were further validated in an independent 94 pairs of ESCC and adjacent control tissues from Chinese Han population.