Cell-mediated immunity and its related cytokines are the most important arm against C. neoformans and during HIV infection, patients exhibit a switch towards a Th2 response inhibiting cellular immune response evidenced by IL-12 and IFN-γ lower levels, as well as, IL-4 and IL-10 increased levels which are associated with progression to AIDS [43–46]. This evidence concerns the gene IL4 and HIV infectious disease.