TNF and Parkinson disease: Microglia may be stimulated by the Toll-like receptor (TLR)-mediated recognition of bacterial and viral particles, for example lipopolysaccharides (LPS) (Boche et al., 2013), the TLR2-driven interaction with α-synuclein (Kim et al., 2013), TLR2/4-binding to Aß (Reed-Geaghan et al., 2009), and serum-derived or locally released TNF-α and IFN-γ, whose combinatorial action was shown to be a crucial inflammatory mediator of dopaminergic cell death in a rodent model of PD (Mir et al., 2008; Barcia et al., 2011).