… that uses terms we can maybe understand:
The genome of all cells in the human body is the same for all of them, regardless their aspect and functions. Therefore, genome cannot fully explain the activity of tissues and organs and their disorders in complex diseases like cancer. It takes a further explanation. Part of this explanation is provided by epigenetics, a field of biology that studies the heredity activity of DNA that does not involve changes in its sequence. That is, if genetics is the alphabet, epigenetics is the spelling that guides the activity of our cells.
From “First Epigenome in Europe Completed” (ScienceDaily, May 30, 2012)