Slowing the cell cycle to increase fetal hemoglobin

In this issue of Blood, Balbin-Cuesta et al 1 identified a population of slow cycling erythroid cells that express high levels of fetal hemoglobin (HbF), described its control by cell cycle regulators, and with these data, suggested that erythroid cells could be manipulated to increase HbF production for the treatment of -hemoglobinopathies.