We first tested our 3 different anti-CXCR4 mAb clones (A145, A120 and A80) for their potential to inhibit the infection of the prototype X4 HIV-1NL4-3 and for purposes of controlling the prototype R5 HIV-1JR-FL in in vitro activated primary PBMC cultures. This evidence concerns the gene CXCR4 and infection.