A preclinical study has indicated that mRNA expression of p14ARF could be reactivated in methylated neuroblastoma cells (18). Other researches have reported that zebularine is an effective inhibitor of p15INK4B and p16INK4a methylation and reactivates these methylated genes leads to cell growth inhibition in AML and T24 bladder carcinoma cells, respectively (19, 20). This evidence concerns the gene CDKN2A and neuroblastoma.