A study using a humanized mouse model with human hematopoietic progenitor stem cells transduced by CCR5-shRNA-expressing lentivirus showed that there was no production of p24 in an ex vivo test after 12 days of infection with CCR5-tropic HIV-1 NL4-3 in CCR5-shRNA+ splenocytes (Shimizu et al., 2010). Here, CCR5 is linked to infection.