Research work in our laboratory has focused on a novel mechanism of acquired drug resistance involving the role of DNA methylation in neuroblastoma. DNA Methylation is an epigenetic mechanism responsible for silencing the gene(s) in a cellular system. Tumor cells become resistant to chemotherapeutic agents by an alteration in methylation patterns of tumor suppressor, drug resistant or DNA repair genes that allow cells to escape the normal process of cell cycle regulation. Understanding the mechanism(s) that modulate methylation patterns of genes and thereby the gene products at genetic & molecular level may provide a more effective approach to circumventing the drug resistance in neuroblastoma and other fatal tumors. Results of these studies may lead to new chemotherapeutic approaches for the effective treatment of neuroblastoma and a variety of childhood tumors.