Another interesting finding in this study is that RASSF1A promoter hypermethylation could significantly downregulated RASSF1A protein expression both in ESCC and GCA, further indicating the possible crucial role of RASSF1A promoter hypermethylation and protein expression in esophageal and gastric cardia carcinogenesis. This evidence concerns the gene RASSF1 and esophageal squamous cell carcinoma.