The pathogenic CCR5/CXCR4 dual-tropic HIV-R3A strain efficiently established infection in humanized mice (Figure 1A), associated with IFN-I induction and ISG expression (Figure 1B&C), increased HLA-DR+CD38+ CD8 T cells (Figure 1D), and CD4 T-cell depletion (Figure 1E). This evidence concerns the gene CXCR4 and infection.