CXCR4 and HIV-1 infection: In HIV-1 infection, FPR2 on the one hand may inhibit viral infection through HIV-1 co-receptor CCR5 and CXCR4 cross-desensitization mediated by activation through glycoprotein fragments,28,29,33,67 but on the other hand can act as a co-receptor for HIV-1 viral entry itself.68