In a severe combined immunodeficiency retroviral gene therapy trial conducted in 2002, four of the patients developed leukemia as a consequence of the treatment; three of the patients recovered after chemotherapy.
Nun ensaio de terapia xénica con retrovirus de inmunodeficiencia combinada grave realizado en 2002, catro dos pacientes desenvolveron leucemia como consecuencia do tratamento; tres dos pacientes recuperáronse despois da quimioterapia.