TLR4 and amyotrophic lateral sclerosis: The astrocyte-regulating factors highlighted above also modulate microglia, including LPS, HMGB1, and the damage-associated molecular pattern (DAMP) factor, hsp70 at TLR4 [101,102,103]; gut microbiome-derived butyrate and HDACi [104]; melatonin production and deactivating effects [77]; ALS susceptibility genes, including mtSOD1 [105], TDP-43 [106], FUS [107] and C9ORF72 repeat [108]; NF-kB and YY1 transcriptional regulation of activation [101,109]; BACE1 and amyloid-β production and clearance [110]; and pro-inflammatory cytokines [101].