Currently used ex vivo hematopoietic stem cell (HSC) gene therapy is a complex and expensive procedure ($500,000-1,000,000 per patient) requiring extensive HSC manipulation and transplantation expertise. Moreover, the intense myelo-conditioning/ablation required to reach clinically relevant HSC engraftment levels, increases toxicity, and prolongs hospitalization. We developed a minimally invasive and readily translatable approach for in vivo HSC gene delivery without leukapheresis, myeloablation, and HSC transplantation. It involves injections of G-CSF/AMD3100 to mobilize HSCs from the bone marrow into the peripheral blood stream and the intravenous injection of HSC-targeting HDAd5/35++ vectors. HSCs transduced in the periphery home back to the bone marrow where they persist long-term. We have used this approach for in vivo HSC transduction to achieve transgene integration or CRISPR/Cas9-mediated HSC genome editing. Current studies involve mouse models for thalassemia, sickle cell disease, hemophilia A, and cancer. Future studies are aimed toward the clinical translation of the in vivo HSC transduction approach. Dr. Lieber collaborates with Drs. Papayannopoulou, Kiem, and Hawkins.