TLR4 is involved in NAFLD development through its binding with LPS and activation of NF-kB pathway [46,47], as demonstrated by the fact that mutant mice with a disruption of the LPS-TLR4 signaling pathway (TLR4 mutant mice) are resistant to liver injury and fibrosis, as well as being protected against diet-induced obesity and insulin resistance [48,49,50]. The gene discussed is TLR4; the disease is obesity due to melanocortin 4 receptor deficiency.