Figure 1.

General view of a gene-therapy approach for β-thalassemia.

Notes: Adult hematopoietic stem and progenitor cells (HSPCs) or induced pluripotent stem cells (iPSCs) can be the object of gene-therapy approaches. (A) The commonly used CD34⁺ HSPCs and subpopulations may be corrected directly by gene therapy. (B) Alternatively, somatic cells can be isolated and reprogrammed to pluripotency, with the resulting iPSCs then being a patient-specific substrate for gene therapy, clonal selection, and lineage-specific differentiation. Excepting circular arrows, solid arrows indicate procedures for HSPCs and hollow arrows those for iPSCs. Circular arrows apply to HSPCs and iPSCs alike. Application of β-thalassemia iPSCs to patients is still pending, as indicated by dashed arrows.