For Sickle celldisease (SCD), a monogenic disorder caused by a mutation in the beta-globin gene(beta S allele) compromising the production of normal adult hemoglobin (Vichinsky et al., 2000), gene therapyapproaches include the ex-vivo transduction of the HSPC forexpressing the intact beta-globin gene, anti-sickling beta-globin, or the fetalgamma-globin. Here, HBB is linked to sickle cell disease.