CCR5 and HIV-1 infection: A small number of people with a 32-bp deletion of the CCR5 gene (CCR5Δ32) have shown to be resistant to HIV-1 infection [57–59], and transplantation of allogeneic bone marrow with homozygous CCR5Δ32 to AIDS patients has shown to be a functional cure with few side effects [29, 60].