HLA-B and carcinoma of esophagus: Interestingly, despite 5-aza-2'-deoxycytidine has shown the ability to demethylate HLA-B locus in a an esophageal carcinoma cell line, both hydralazine and the nucleoside analog which is the prototype demethylating agent failed to demethylate the promoter in the SW480 cell line despite 5-aza-2'-deoxycytidine increased gene expression.