TLR4 and multiple system atrophy: Experimental studies showed that Toll-like receptor 4 (TLR4), a member of highly conserved molecules that recognize pathogen-associated molecular patterns, played an important role in the microglial α-Syn clearance suggesting that up-regulation of TLR4 in microglia may constitute a relevant target for MSA therapy (Stefanova et al. 2011; Fellner et al. 2013).