Cutaneous leishmaniasis caused by the protozoan Leishmania braziliensis exhibits two dominant inflammatory responses in cutaneous lesions: Interferon-γ (IFN-γ)-mediated signaling, which promotes parasite control, and cytolysis mediated by cytotoxic CD8+ T and NK cells, which promotes increased pathology. The gene discussed is IFNG; the disease is cutaneous leishmaniasis.