Almost all cells in the human body contain a complete copy of the genome with an estimated number of 25,000 genes. The sequences of these genes make up about three percent of the genome and comprise the inherited set of genetic information. The genome also contains information that determines when and where in the organism a given gene is active. This is the epigenetic information. Genomics is the study of DNA sequences and the epigenetic information of gene regulation.
Acta Pathologica Microbiologica Et Immunologica Scandinavica, 2007, Vol 115, Issue 10, p. 1037-8