Recent studies using KO models have shown that MKP-2 protects against septic shock17 and plays a role in regulating T cell function.18 Moreover, MKP-2 deletion mice developed in our laboratory have been shown to be highly susceptible to parasite infection with Leishmania mexicana and Toxoplasma gondii due to alterations in macrophage iNOS/arginase expression.19 20 Bone marrow-derived macrophages that have been stimulated with lipopolysaccharide (LPS) showed an increase in proinflammatory IL-6, IL-12, TNFα and a decrease in anti-inflammatory IL-10 in the absence of MKP-219. The gene discussed is DUSP4; the disease is parasitic infectious disease.