Regarding this, we have recently reported that a transcriptional gene silencing (TGS) approach using a short hairpin (sh) RNA, which is called shPromA (Figure 2), resulted in limited CXCR4-associated depletion of bone marrow CD34+ cells following CCR5-tropic HIV infection in humanized mice (Figure 3). The gene discussed is CXCR4; the disease is HIV infectious disease.