CD34 and cancer: The first licenses for ex vivo gene modified cell therapy trials were issued in 2003 to Johnson & Johnson Research Pty Ltd., (DNIR-170) for autologous CD34+ hematopoietic progenitor cells (HPC) transduced with a retroviral vector containing an anti-HIV-1 ribozyme, and The Children’s Hospital at Westmead (DNIR-179) for autologous CD34+ HPC transduced with a retroviral vector containing genes to provide resistance to alkylating drugs used in cancer therapy.