In myelodysplastic syndrome (MDS), 5-Aza-CdR can re-activate the expression of the p15INK4B gene in MUTZ-1 cells by demethylation of the p15INK4B gene through inhibition of DNMT3a gene expression which is a mechanism of 5-Aza-CdR in the treatments of MDS (Tong et al., 2004). This evidence concerns the gene DNMT3A and myelodysplastic syndrome.