Inclusion Criteria: * Patients or parent(s)/legal guardian(s) willing and able to complete the informed consent process and comply with study procedures and visit schedules. * Diagnosis of beta-thalassemia and a history of RBCs transfusions. * Documented baseline, or pretransfusion, Hb≤7 g/dL. * Availability of an adequate and well-documented transfusion history. Exclusion Criteria: * Active bacterial, viral, fungal, or parasitic infection. * A white blood cell (WBC) counts\<3×10\^9/L, and/or platelet counts\<100×10\^9/L not related to hypersplenism. * Uncorrected bleeding disorder. * Presence of severe diseases that judged not compatible with the study procedures, such as severe hepatic disease, kidney disease, lung disease, and/or cardiovascular disease. * Uncontrolled seizure disorder. * Any evidence of severe iron overload that, in the investigator's opinion, warrants exclusion. * Prior autologous hematopoietic stem cell transplantation. * Prior receipt of gene therapy.