These genome-edited cells have a selective advantage during CCR5-tropic or/and CXCR4-tropic HIV-1 infection and the lenti-X4R5-Cas9 vectors did not have non-specific cleavage or cytotoxicity after both CXCR4 and CCR5 disruption, which showed a specific targeting of HIV-1 receptors [72]. Here, CCR5 is linked to HIV-1 infection.