This includes the activation of NK cells and CD8+ T cells seen during Toxoplasma gondii infection and the pro-apoptotic effects of Trypanosoma cruzi infection as well as the Kunitz type protease inhibitor from Echinococcus granulosus, which was shown to induce tumor cell apoptosis in a mouse melanoma model (14, 15). The gene discussed is CD8A; the disease is melanoma.