APAF1 and myelodysplastic syndrome: When aberrant methylation occurs in the promoter of genes that suppress tumorigenesis, it can lead to the resistance to apoptosis and progression of cancer19.Since theAPAF1gene, a TSG, is rarely mutated, promoter hyper methylation appears to be the mechanism underlying its inactivation.20In this study, we examined expression of APAF1 in MDS and found that APAF1 mRNA level was diminished in 53.7% of MDS cells.