CD34 and cystinosis: Gene therapy for cystinosis involves the use of autologous CD34+-enriched cell fractions transduced with LV vector encoding hCTNS. Although the intravenous administration of AAV vector encoding hCTNS gene may be effective in limited cases, such as kidney disease, one dose of autologous CD34+-enriched cell fractions transduced with LV vector encoding hCTNS gene is considered to have beneficial effects throughout the body, while several rounds of intravenous administration are needed.