Help is at hand for scientists struggling to make sense of the current flood of human genome sequence data: the Encyclopedia of DNA Elements (ENCODE). Now an accompanying user guide is available.

The guide — published by a consortium composed of dozens of international research groups — describes data from more than 100 human cell types that define the functional elements in the genome, including more than 2 million regulatory regions. The team mapped RNA transcribed from DNA; protein-binding sites; and 'epigenetic' modifications to DNA's structure, such as DNA methylation patterns. Together, these should help researchers work out possible roles for sequence variants that have been linked to a disease.

For example, ENCODE data helped to clarify how a DNA region upstream of a cancer-promoting gene called c-Myc regulates the gene: by attracting and binding proteins that enhance its expression.

PLoS Biol. 9, e1001046 (2011)