Decitabine also known as 5-Aza-2′-Deoxycytidine is a Dnmt inhibitor shown to alter gene expression. 5-Aza-2′-Deoxycytidine has been reported to cause phosphorylation inhibition of 2′-deoxycytidine in certain cells and the incorporation of 2′-deoxycytidine into DNA. Experiments have shown that 5-Aza-2′-Deoxycytidine induces changes in the differentiated state of cultured mouse embryo cells and additionally inhibits methylation of newly synthesized DNA. DNA methylation has been noted to be important in determining apoptotic susceptibility to histone deacetylase inhibitors, and its prevention by 5-Aza-2′-Deoxycytidine can cause gene silencing and transcriptional repression. Other studies suggest that cell exposure to 5-Aza-2′-Deoxycytidine causes a change in replication timing, reactivation of repressed genes, and decondensation of heterochromatin. Furthermore, 5-Aza-2′-Deoxycytidine demonstrates the ability to induce histone hyperacetylation in murine centromeric heterochromatin and also affect intranuclear distribution of histone deacetylase.