The human β-globin locus. (A) The β-globin locus on chromosome 11 embedded in chromatin is shown. (B) A linear map with the globin LCR and its hypersensitive (HS) sites is indicated by the vertical arrows. The structural ϵ-, γ-, δ-, and β-globin genes as well as the locations of the olfactory receptor (OR) genes are shown.