Intriguingly, we found that HBB −28 (A>G) mutation repairing efficiency was about 20% in the constructed cell line and primary skin fibroblast cells. Although 10.7% of the repaired skin fibroblast cells were heterozygous, it is still able to cure anemia (Dever et al., 2016). Whether base editors will be equally or more efficient in human hematopoietic stem cells is still under investigation. High repairing efficiency in human hematopoietic stem cells will lead to new therapeutics for β-thalassemia intermedia and β-thalassemia major patients with HBB −28 (A>G) mutation.