Figure 1.

Diagram of a hypothetical gene locus, illustrating how multiple distributed cis-regulatory modules can contribute to total expression of the green gene. For the purposes of this diagram, patterning is ignored, and output is considered purely quantitatively. Only regulatory elements of green are shown; although “shadow” enhancer D is nearer to the red gene, it specifically regulates green. Percentages refer to the amount of gene expression driven by each element or combination of elements, relative to the entire gene locus.