Host factors that are associated with delayed seroconversion or reduced susceptibility to HIV infection include CCR5, CCR2b, ERAP2, MX2, TIM3, TLR3, APOBEC3 family, TRIM family, HLA (DQB1*03:02, HLA-B*57 and HLA-B*35, HLA-E, HLA-F, CD1a-e, MR1), Vitamin D receptor (VDR), and IRF-1. Here, IRF1 is linked to HIV infectious disease.