Defining a genomic radius for long-range enhancer action: duplicated conserved non-coding elements hold the key

Many conserved non-coding elements (CNEs) in vertebrate genomes have been shown to function as tissue-specific enhancers. However, the target genes of most CNEs are unknown. Here we show that the target genes of duplicated CNEs can be predicted by considering their neighbouring paralogous genes. This enables us to provide the first systematic estimate of the genomic range for distal cis-regulatory interactions in the human genome: half of CNEs are >250 kb away from their associated gene.