Host susceptibility studies in mice have shown that production of the Th1-type cytokines IFN-γ and IL-12, as well as the pro-inflammatory cytokine TNF-α confers protection against cryptococcosis (Kawakami et al. 1996a, Kawakami et al. 1996b, Kawakami et al. 1996c, Decken et al. 1998, Herring et al. 2002). This evidence concerns the gene IFNG and cryptococcosis.