Induction of HbF by pomalidomide. Treatment with pomalidomide during in vitro differentiation of primary human erythroid cells leads to the concerted suppression of several known repressors of fetal globin gene expression. This suppression is noted at both the RNA and protein levels and is most pronounced early in differentiation. This leads to increased levels of HbF and decreased levels of adult hemoglobin (HbA) in mature erythrocytes. Professional illustration by Patrick Lane, ScEYEnce Studios.