CXCR4 and HIV-1 infection: On the other hand, EVs can enhance HIV-1 infection by (I) Transferring of co-receptors CCR5 and CXCR4 to null cells; (II) Camouflaging the virus from immune surveillance through physical association; (III) Transferring of HIV-1 components (viral proteins and RNAs) to recipient cells, which induces further outcomes including T cell activation and apoptosis.