VDR and HIV-1 infection: Therefore, to establish an association between VitD and natural resistance to HIV-1 infection, we compared the levels of i) plasma VitD; ii) VDR mRNA; iii) mRNA of the cytokines Interleukin (IL)-10, Transforming Growth Factor beta (TGB-β), Tumor Necrosis Factor alpha (TNF-α) and IL-1β, and iv) mRNA of the antimicrobial peptides HBD-2 and HBD-3 in peripheral blood mononuclear cells (PBMCs) and in mucosa samples of HESN, HC and SP individuals.