A locus control region (LCR) is a long-range cis-regulatory element that enhances expression of linked genes at distal chromatin sites. It functions in a copy number-dependent manner and is tissue-specific, as seen in the selective expression of β-globin genes in erythroid cells.[1] Expression levels of genes can be modified by the LCR and gene-proximal elements, such as promoters, enhancers, and silencers. The LCR functions by recruiting chromatin-modifying, coactivator, and transcription complexes.[2] Its sequence is conserved in many vertebrates, and conservation of specific sites may suggest importance in function.[2] It has been compared to a super-enhancer as both perform long-range cis regulation via recruitment of the transcription complex.[3]