HBG1/HBG2 gene therapy (St. Jude Children 's Research Hospital)

Cas9 editing of the γ-globin gene promoters in hematopoietic stem cells (HSCs) increases red cell HbF by ≤40%. No deleterious effects on hematopoiesis or off-target mutations were detected 16 weeks after xenotransplantation of edited HSCs.