Because ICAM-1 upregulation was not observed in mice deficient in RAG-1 or IFN-γ on day 6 after infection with PbA [163], the Th1 type cytokines IFN-γ and lymphotoxin, in synergy with TNF from macrophages [163], [164], may induce ICAM-1 expression throughout the brain microvasculature of ECM-susceptible mice, both during ECM and hyperparasitemia. This evidence concerns the gene TNF and infection.