Bio Mol: Epigenetics

Epigenetics refers to the study of different mechanisms controlling gene expression independently from the DNA sequence. In fact there are heritable modifications in gene expression, going from one generation to another one, which are not caused by what is coded in the genome itself.
The role of epigenetic factors might be an extra control on gene regulation, in cell differentiations and cell developments. Potentially epigenetic abnormalities could be causative factors in cancer, genetic disorders, autoimmune diseases and aging.

DNA methylation and histone modifications are 2 basic principles of epigenetics. Actually when methyl groups attach to the histones, they can affect the expression of the DNA's genetic code, by turning special genes on or off. Distinct methylation and histone patterns exist in every cell, constituting a sort of second genome, the epigenome.