Much of this effect is due to activation by double stranded viral RNA of Toll-like receptor 3 (TLR3) on both neurons and immune system cells as part of the defence mechanism against viral infections (Brown and Derkits, 2010; Daffis et al., 2008; De Miranda et al., 2010; Meyer et al., 2008; Takeda and Akira, 2007). The gene discussed is TLR3; the disease is viral infectious disease.