CCR5 and HIV-1 infection: One can see that a huge research effort has been dedicated to genetic association studies, and this is logical since this experimental approach deals with real invivo data, i.e., cohorts of patients and HIV-1 infection invivo. Nevertheless, it was slightly surprising to observe that the main signals found by GWAS, in the HLA and CCR5 loci, had already been identified by previous candidate gene approaches.