HLA-DRB1 and HIV infectious disease: Although there is no association between DRB1*09:01 and HIV infection, new associations between the DQA1*03:02 and DRB1*09:01 allelic variants and HIV infection have been identified, which could be attributed to an increased affinity and specificity of the peptide-binding region (PBR), influencing the recognition of pathogen-derived antigens [33].