In NASH, TLR4 (that recognizes LPS, a gram-negative bacteria wall component), TLR5 (known to recognize bacterial flagellin from invading mobile bacteria), TLR2 (that recognizes many bacterial, fungal, viral, and endogenous substances) and TLR9 (a specific receptor for double-stranded bacterial DNA) have been shown to play a key pathogenetic role [281]. Here, TLR4 is linked to metabolic dysfunction-associated steatohepatitis.