CXCR4 and HIV-1 infection: Third-generation lentiviral vectors have become safer and have been used to protect T cells from HIV-1 infection by transducing different antiviral genes, such as modified restriction factors APOBEC3G-D128K (56) and TRIM5α-CypA (57), CCR5-interfering RNAs (58), fusion inhibitory peptides (C34-CXCR4 clinical trial), or a combination of sh5 and C46 (59).