Response elements are short sequences of DNA within a gene promoter or enhancer region that are able to bind specific transcription factors and regulate transcription of genes.
A hormone response element (HRE) is a short sequence of DNA within the promoter of a gene, that is able to bind to a specific hormone receptor complex and therefore regulate transcription.
[1] The sequence is most commonly a pair of inverted repeats separated by three nucleotides, which also indicates that the receptor binds as a dimer.
A gene may have many different response elements, allowing complex control to be exerted over the level and rate of transcription.
[2] HRE are used in transgenic animal cells as inducers of gene expression.