Importantly, for moving forward in evaluating whether modified B cells could provide sufficient eCD4-Ig-KiHR in vivo to control HIV-1 infection, culture supernatants demonstrated robust anti-HIV-1 activity against three HIV-1 isolates of both CXCR4 and CCR5 tropisms (Figure 5, Figure 6C and 6C). This evidence concerns the gene CXCR4 and HIV-1 infection.