The expression of CTAs is normally restricted to gametogenic tissue but is often reactivated in the tumorigenic setting. This tumorigenic reactivation is thought to be due to global demethylation events during tumorigenesis. To test this, we employed an affymetrix microarray in the hypermethylated colorectal carcinoma tumor-derived cell line, HCT116, following 5-aza-2'-deoxycytidine treatment. We used microarray analysis to uncover genes whose expression is modulated by DNA methylation in the colorectal carcinoma tumor derived cell line, HCT116. HCT116 cells were exposed to 5-aza-2'-deoxycytidine for 72 hours. Total RNA was isolated and hybridized on to Affymetrix microarrays.