CCR5 and HIV-1 infection: The 5TM ccr5Δ32 splice variant complexes with and retains CCR5 in the ER, so the ccr5Δ32/ccr5Δ32 genotype has been linked with a phenotype that is “highly” protected from HIV-1 infection, whereas the CCR5/ccr5Δ32 genotype confers only “relative” protection [31].