Sickle cell anemia (SCA) and b-thalassemia (Cooley’s Anemia, CA) arise from genetic defects in production of the adult β chain of hemoglobin, and together constitute the most commonly inherited monogenic disease. It has been known for decades that generation of excess fetal γ-globin chains in adult red blood cells reduces morbidity and mortality of these diseases, but γ-globin inducing agents in current use for treatment are cytotoxic antineoplastic agents that exhibit limited beneficial effects coincident with often debilitating side effects; furthermore, all current therapeutics pose potential risks for carcinogenesis. Only during the past decade have molecular pathways begun to emerge that lead to γ-globin gene silencing in adults. The first identified of these molecular complexes (DRED) binds to the γ-globin promoters and comprise a core tetrameric epigenetic modifying machine: a heterodimer of two nuclear receptors (TR2 and TR4) bind to specific regulatory sequences, and they in turn carry to these regulatory sites DNA methyltransferase 1 and lysine-specific histone demethylase 1 (LSD1), an enzyme known to confer epigenetic gene silencing by demethylation of histone H3 lysine 4. We found in human erythroid progenitor cells and in transgenic mice bearing the human β-globin locus that the loss of LSD1 function leads to robust induction of human fetal γ-globin gene expression, demonstrating that LSD1 plays a critical role in γ-globin silencing. These preclinical studies provide the initial proof of principle that therapeutics capable of inactivating LSD1 should be efficacious for the treatment of SCA and CA, and also indicates that TC can serve as a direct or lead compound for developing future therapeutics which are safer and more beneficial than current γ-globin inducing agents.