CCR5 and HIV-1 infection: The CCR5-Δ32 mutation along with single nucleotide polymorphisms (SNPs) in the CCR5 promoter and the CCR2-V64I mutation have been included in seven human haplogroups (HH) previously associated with resistance/susceptibility to HIV-1 infection and different rates of AIDS progression [31]. In vitro studies have demonstrated that HIV-1 can use alternative coreceptors, such as CCR2 [32].