The epigenetic code is hypothesised to be a defining code in every eukaryotic cell

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 consisting of the specific epigenetic modification in each cell. It consists of histone modifications defined by the histone code

Histone code

The histone code is a hypothesis that the transcription of genetic information encoded in DNA is in part regulated by chemical modifications to histone proteins, primarily on their unstructured ends. Together with similar modifications such as DNA methylation it is part of the epigenetic code...

 and additional epigenetic modifications such as DNA methylation

DNA methylation

DNA methylation is a biochemical process that is important for normal development in higher organisms. It involves the addition of a methyl group to the 5 position of the cytosine pyrimidine ring or the number 6 nitrogen of the adenine purine ring...

. The base for the epigenetic code is a system above the genetic code

Genetic code

The genetic code is the set of rules by which information encoded in genetic material is translated into proteins by living cells....

of a single cell. While in one individual the genetic code in each cell is the same, the epigenetic code is tissue and cell specific . The epigenetic code can be multidimensional in nature. It could include any of the three major cellular macromolecucles; namely, DNA (code independent), RNA, and/or protein. In some ciliates potential structural codes have also been suggested .