TLR4 and alcohol abuse: Specifically, the increased gut permeability due to alcohol abuse leads to higher lipopolysaccharide (LPS) concentration into portal blood flow which bind to Toll-like receptor 4 (TLR4) and activate nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) stimulating in turn, pro-inflammatory cytokines release, reactive oxygen species (ROS) production, and oxidative stress.