DNA methylation 40 years later: Its role in human health and diseaseThis manuscript is dedicated to the memory of Prof. Eduardo Scarano, who actively worked at LIGB in Naples, until his untimely death in 1986. He was one of the first scientists to hypothesize that DNA methylation would have a profound effect on gene expression. We recognize his scientific legacy.

A long path, initiated more than 40 years ago, has led to a deeper understanding of the complexity of gene regulation in eukaryotic genomes. In addition to genetic mechanisms, the imbalance in the epigenetic control of gene expression may profoundly alter the finely tuned machinery leading to gene regulation. Here, we review the impact of the studies on DNA methylation, the primadonna in the epigenetic scenario, on the understanding of basic phenomena, such as X inactivation and genomic imprinting. The effect of deregulation of DNA methylation on human health, will be also discussed. Finally, an attempt to predict future directions of this rapidly evolving field has been proposed, with the certainty that, fortunately, science is always better than predictions. 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]