To respond or not to respond to hydroxyurea in thalassemia: a matter of stress adaptation?

In hereditary hemoglobinopathies, such as sickle cell anemia (SCA) and beta-thalassemia (BT), the absolute level of fetal hemoglobin (HbF) production is a critical predictor of severity. High HbF is protective against sickling and vaso-occlusive complications in SCA, and high levels of gamma-globin