Gene therapy is becoming a real therapeutic chance in some genetic disorders. The first candidates to this approach are genetic diseases which involve hematopoiesis, because of the facility for the collection and the manipulation of hematopoietic progenitors. Apheresis techniques, which are able to collect a great number of mononuclear cells from peripheral blood, are ideal for obtaining a large number of cells which can be transfected. Future uses of gene therapy techniques could be: the treatment of hematopoietic genetic disorders, procedures of gene marking, and the manipulation of normal hematopoietic cells with the objective of increasing their resistance to myelotoxic drugs.