Figure 3.
Regulation of fetal hemoglobin (HbF) production. (a) Timing of β-like globin subunit switching during human ontogeny. The embryonic, fetal, and adult stages are shown in blue, green, and red, respectively. (b) Regulators of hemoglobin switching including BCL11A, KLF1, MYB, TR2, TR4, LSD1, HDAC1, and HDAC2 as well as their modes of proposed regulation are depicted here. Some factors, including the BCL11A complex repress γ-globin through indirect mechanisms of action and are therefore shown with dotted lines. BCL11A binding sites are indicated with an asterix. Corepressor complexes that associated with BCL11A and other regulators are depicted in red.