Like bacteria, eukaryotes use gene regulatory proteins
(activates and repressors) to regulate the expression of their
genes but in somewhat different way. The DNA sites to witch the
eukaryote gene activates bound were originally termed enhancers,
since their presence “enhanced”, or increased, the rate of
transcription dramatically. It came as a surprise when, in 1979,
in was discovered that those activator proteins could be bound
thousands of nucleotide pairs away from promoter.