Numerous studies have shown that HU can effectively lower the blood transfusion frequency in thalassemia patients (23, 39, 40, 43), raise the level of Hb (11, 28, 29, 31), improve the HbF level (32, 48, 52), and improve their quality of life (53, 54). The gene discussed is GSTM1; the disease is thalassemia.