These results together with the fact that TNF-α RNA transcripts have been described in the CNS and that intracerebral infusion of soluble type I TNF-α receptor reduced trypanosome-induced neurodegeneration (Quan et al., 2003), suggest that TNF-α production could play a role in CNS disorders and that TNF-α and other cytokines might contribute to the generation of somnogenic molecules such as IL-1 (Pentreath et al., 1994). Here, TNF is linked to central nervous system disorder.