Organisms rely upon the contents of their DNA for the genetic recipes necessary for life. However, the way in which genes can impact the phenotype of the organism is not strictly limited to variance in nucleotide sequence. Epigenetics is the study of heritable changes in gene function that do not involve changes in the DNA sequence. Rather, epigenetics often considers modifications to the chromatin/chromosome that affect gene activity and expression. Covalent modifications of either DNA (such as cytosine methylation and hydroxymethylation) or of histone proteins (such as lysine acetylation, lysine and arginine methylation, serine and threonine phosphorylation, and lysine ubiquitination and sumoylation) can play significant roles in altering gene expression, as necessary for development or transgenerational inheritance, or cause fundamental detrimental changes, such as in many cancers. For a review of epigenetic concepts, check out the Epigenetics entry page made available by Nature Scitable. Thus, this topic can be applied to many different Biology sub-disciplines. Depending on your interests, you can easily find examples pertaining to cancer studies or evolution or tissue/organ patterning (just to name a few topics!). The following news feeds may help inspire you to find topics you would like to explore more fully.