Epigenomics Is the study of all epigenetic changes in the cell The epigenome is a multitude of chemical compounds that instruct the genome what to do. The human genome is a complete assembly of DNA about 3 billion base pairs that makes each individual unique. DNA holds the instructions for building proteins that carry out a variety of functions in a cell. Epigenome is made up of chemical compounds and proteins that attach themselves to the DNA and direct actions such as turning genes on or off, controlling the protein production in particular cells. When some epigenomic compounds attach themselves to the DNA they modify its functions and they mark the genome. These marks will not change the sequence of the DNA. But, they change the way these cells use the DNA's instructions and these marks are sometimes passed on from cell to cell as cells divide. There are chances they can be passed down from one generation to the next.