Schematic representation of the human globin gene clusters. Theα-like globin cluster (top) is situated near the telomeric region of the short arm of chromosome 16 and includes the ζ, α2, and α1 globin genes, which are under the control of an upstream remote regulatory region, HS-40 (so-called because it is a DNase I hypersensitive site located approximately 40 kb upstream of the 5′ end of the ζ globin gene). The β-like globin cluster (bottom) is interstitial and located on the short arm of chromosome 11; expression of the genes in this cluster is under the control of a group of remote regulatory elements/DNase I hypersensitive sites collectively known as the locus control region (LCR). Pseudogenes and the θ globin gene, whose functional significance is unknown, are not represented. To make visualization of them easier, the globinlike genes are represented over a larger space of genome than they actually span.