TLR4 and amyotrophic lateral sclerosis: Exosomal miRNA-146a was found to represses TLR2 expression in Alzheimer’s disease [41], exosomes derived from pancreatic cancer contain high levels of miRNA-203, which down-regulates TLR4 and cytokines in DCs [47], exosomes abundant in miR-124 in amyotrophic lateral sclerosis are associated with persistent NF-κB activation and up-regulated expression of inflammatory factors including TLR4 [40].